RU2776781C1 - System and method for tuned linear accelerators - Google Patents

Abstract

FIELD: linear accelerators.

SUBSTANCE: invention relates to linear accelerators. The frequency control system for a tunable linear accelerator comprises an RF source configured to generate an RF signal; RF frequency control circuit connected to the RF source and configured to adjust the frequency of the RF signal; an accelerating structure configured to accelerate the particle beam in response to the RF signal; and a control logic configured to: receive a plurality of settings over time for the RF source; maintaining a settings history including the latest few settings from said set of settings for the RF source; adjusting the current RF signal in response to multiple settings; and adjusting the current RF setpoint of the frequency control loop in response to a combination of at least two of the most recent settings at various points in time in history, said set of settings being energy level settings for the RF source.

EFFECT: expansion of the range of regulation of the parameters of the linear accelerator.

18 cl, 10 dwg

Description

Technical field

The present invention relates to tunable linacs, trigger distribution systems, and frequency control systems for tunable linacs.

State of the art

Linear accelerators are used in complex systems such as medical systems, security screening systems, communications and radar. The linac can be used as part of a system that generates X-rays or amplifies a radio frequency (RF) or microwave electromagnetic signal. Some linacs generate pulses of accelerated particles by means of pulsed power applied to a particle source and power to an RF source. Some linacs have fixed levels and times for the power delivered to the particle source and the power delivered to the RF source to fix the energy and dose rate (eg, time and amplitude) for the pulses. Other linacs can switch between two or more factory modes, in which each mode has a corresponding power delivered to the particle source and a power delivered to the RF source. The power supply time is the same for each mode. Moreover, the mode switching is carried out based on a predetermined pattern, alternating between the two modes.

Disclosure of the essence of the invention

The present invention proposes a frequency control system for a tunable linear accelerator, comprising:

An RF source configured to generate an RF signal;

RF frequency control circuit connected to the RF source and configured to adjust the frequency of the RF signal;

an accelerating structure configured to accelerate the particle beam in response to the RF signal; and

control logic configured to:

receiving a plurality of settings over time for the RF source;

maintaining a settings history including the latest few settings from said set of settings for the RF source;

adjusting the current RF signal in response to multiple settings; and

adjusting the current RF setpoint of the frequency control circuit in response to a combination of at least two of the most recent settings at different times in history,

wherein said set of settings are energy level settings for the RF source.

In embodiments, the control logic is operable to initialize the most recent settings in the history so far with the RF source default setting for each of the most recent settings.

The control logic is configured to:

subdividing settings in history into energy level categories;

selecting a category from the energy level categories with the most settings; and

adjusting the current RF setpoint of the frequency control loop in response to the energy level associated with the selected category.

The control logic is configured to:

combining energy levels associated with settings in history into a combined energy level; and

adjusting the current RF setpoint of the frequency control loop in response to the combined energy level.

The control logic is configured to:

combining the energy levels associated with settings in history into a combined energy level using weighting factors that increase with the energy level, and

adjusting the RF setpoint of the frequency control loop in response to the combined energy level.

The history spans times less than or equal to 0.2 seconds.

The control logic is configured to:

receiving an indication of an energy level for the incoming RF pulse; and

adding an indication of the energy level to the history.

The control logic is configured to:

receiving a pulse timing indication for the incoming RF pulse of the RF signal; and

changing the sampling timing of the one or more RF feedback signals in the RF frequency control loop based on the pulse timing indication.

The present invention also provides a method for operating a tunable linac, comprising:

using an RF source to generate an RF signal in response to a plurality of energy level settings for the RF source over time;

maintaining a history of a plurality of energy level settings including the most recent few of said plurality of energy level settings for the RF source;

accelerating the particle beam in response to the RF signal; and

adjusting the current setpoint of the RF source in response to a combination of at least two of the most recent settings at different times in history.

In embodiments, the method further comprises:

receiving a pulse timing indication for the incoming RF pulse; and

changing the sampling timing of the RF feedback signals in the frequency control loop for the RF source based on the pulse timing indication.

The method further includes initializing the most recent settings in the history of the plurality of energy level settings with a default setting for each of the most recent settings.

The method further includes dividing the history energy level settings into categories according to the energy level;

selecting the category of energy level settings with the largest number of recent energy level settings at the moment; and

adjusting the current RF source setpoint in response to the selected category.

The method further includes:

combining a plurality of history energy level settings into a combined energy level; and

adjusting the current RF source setpoint in response to the combined energy level.

The method further includes:

combining multiple energy level settings in history into a combined energy level using weighting factors that increase with energy level, and

adjusting the current RF source setpoint in response to the combined energy level.

Maintaining a settings history includes maintaining a history spanning times less than or equal to 0.2 seconds.

The method further includes:

receiving an indication of an energy level for the incoming RF pulse; and

adding an indication of the energy level to the history.

The present invention also provides a frequency control system for a tunable linac, comprising:

means for generating an RF signal in response to a plurality of energy level settings for means for generating an RF signal over time;

means for maintaining a history of a plurality of energy level settings including the most recent few of said plurality of energy level settings for the RF source;

means for accelerating the particle beam in response to the RF signal;

means for adjusting the frequency of the RF signal; and

means for adjusting a current setpoint of means for adjusting the frequency of the RF signal in response to a combination of at least two of the most recent settings at different times in history.

In embodiments, the system further comprises means for accelerating the particle beam in response to an RF signal.

Brief description of the drawings

In FIG. 1A-C show schematic diagrams of tunable linacs in accordance with some embodiments.

In FIG. 1D is a schematic diagram of a custom system according to some embodiments.

In FIG. 2A-2H are timing diagrams depicting various signals in a tunable linac, in some embodiments.

In FIG. 3A-3C are schematic diagrams of a trigger distribution system in a tunable linac, in accordance with some embodiments.

In FIG. 4A-4B are timing diagrams of signals in a trigger distribution system in a tunable linac, in accordance with some embodiments.

In FIG. 5A-5D are schematic diagrams of the input and output circuits of a trigger distribution system in a tunable linac, in accordance with some embodiments.

In FIG. 6A-6B are block diagrams illustrating methods of operating a tunable linac, in accordance with some embodiments.

In FIG. 7A-7B are block diagrams illustrating methods of trigger signal distribution in a tunable linac, in accordance with some embodiments.

In FIG. 8A and 8B are schematic diagrams of frequency control systems in a tunable linac, in accordance with some embodiments.

In FIG. 8C is a schematic diagram of a frequency control system in accordance with some embodiments.

In FIG. 9 is a block diagram illustrating methods for adjusting the RF source frequency of a tunable linac, in accordance with some embodiments.

In FIG. 10 is a schematic diagram of a 2D x-ray imaging system in accordance with some embodiments.

Implementation of the invention

Linacs typically use a particle source configured to generate a particle beam, such as an electron source. The particle beam is directed through the accelerating structure. The accelerating structure is a resonant structure that uses an input RF signal to accelerate particles in a particle beam. The beam of accelerated particles is generated by operating the particle source in a pulsed mode to generate a particle pulse directed at the accelerating structure. The RF signal accelerates the particles to generate a beam of accelerated particles. As will be described in more detail below, the particle source and the RF source can be independently controlled during operation. In addition, the operation time of the particle source and the RF source and/or the frequency control of the RF source will be described in more detail below.

In FIG. 1A-1C show schematic diagrams of tunable linacs in accordance with some embodiments. As shown in FIG. 1A, a linac system 100a (or accelerator-based system or system) comprises a particle source 102, an accelerating structure 104, and an RF source 108. etc.

Particle source 102 is a device or system capable of generating particle beam 114 in response to a particle power signal. For example, particle source 102 may be an electron gun, ion source, or other device capable of generating a beam of charged particles. The particle source 102 is configured to generate a particle beam 114 in response to a particle power signal 118 . In one example, particle source 102 may be a diode electron gun that has two separate electrical potentials, including a cathode and focusing electrode connected to a first voltage and an anode connected to a second voltage. In another example, the particle source 102 may be a triode electron gun that has three separate electrical potentials, including a cathode and a focusing electrode connected to a first voltage, an anode connected to a second voltage, and a control grid, typically located above the surface of the cathode, connected to a third voltage between the first voltage and the second voltage.

The particle power signal 118 is a signal that causes the particle source 102 to generate a particle beam 114 . For example, in some embodiments, the particle power signal 118 comprises a high voltage pulse, such as a pulse having an amplitude of 3 kilovolts (kV) to 39 kV. The high voltage pulse may have a pulse width of approximately 2-5 microseconds (µs); however, in other embodiments, the pulse width may be different.

The particle power source 106 is a device or system capable of generating a particle power signal 118 . The particle power source 106 includes a pulse generating circuit that includes circuitry for controlling at least one of amplitude, delay, and pulse width in the particle power signal 118 . For example, particle power source 106 may include high voltage power sources, solid state or other high voltage/high current switches, transformer networks, inductor-capacitor (LC) or resonant pulse shaping networks, one or more energy storage devices such as capacitors, inductors etc. The particle power source 106 may also include control logic, as will be described below.

In some embodiments, the particle power source 106 is configured to change the pulse generation of the particle power signal 118 such that the current pulse has one or more of the amplitude, delay, and pulse width different from those of the previous pulse. That is, the characteristics of the pulses may differ from pulse to pulse. In some embodiments, particle power source 106 is configured to generate pulses having a discrete number of parameters. For example, the pulse amplitude may be selected from a limited set of two or more amplitudes. However, in other embodiments, the selection may be continuous, variable through analog or digital tuning, substantially continuous in digital steps that are relatively small, or the like. Although amplitude has been used as an example of a parameter that can be changed in a discrete and continuous manner, in other embodiments, other parameters can be changed in a similar manner.

In some embodiments, the particle power signal 118 may not be the signal that provides power to generate the particle beam 114, but the signal that the particle source 102 modulates. For example, particle power signal 118 may be a control signal, such as a mains voltage signal for a triode electron gun. In this example, particle source 102 may include a connection to a high voltage DC source (not shown) configured to provide a high cathode voltage. The particle power signal 118 modulates the particle beam 114 .

RF source 108 is a device or system configured to generate an RF signal 120 in response to an RF power signal 122. For example, RF source 108 may be a magnetron, a low power RF source coupled to a klystron RF amplifier, or another RF source 108 capable of generating microwave RF signals in L, S, C, X, or other frequency bands such as RF signal 120. Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter (1 m) to one millimeter (1 mm) with frequencies ranging from 300 megahertz (MHz; 1 m) to 300 gigahertz (GHz; 1 mm), including ultra high frequency (UHF; 300 MHz to 3 GHz), ultra high frequency (UHF; 3 to 30 GHz), and extremely high frequency (EHF; millimeter wave; 30 to 300 GHz). With an electromagnetic energy frequency in the range of approximately 1 GHz to 100 GHz, the microwave spectrum can be further divided into bands such as L (1-2 GHz), S (2-4 GHz), C (4-8 GHz), X (8 -12GHz), Ku (12-18GHz), K (18-26.5GHz), Ka (26.5-40GHz), Q (33-50GHz), U (40-60GHz), V (50-75 GHz), W (75-110 GHz), F (90-140 GHz) and D (110-170 GHz). The L band is associated with UHF, the S to Ka bands are associated with UHF, and the Q through D bands are associated with EHF.

RF power signal 122 is a signal that causes RF source 108 to generate RF signal 120. In some embodiments, RF power signal 122 comprises a high voltage pulse, such as a pulse generated by a magnetron having an amplitude of approximately 20 kV to 45 kV, or a pulse generated by a klystron having an amplitude of approximately 100 kV to 135 kV. The high voltage pulse may have a pulse width of approximately 25 microseconds (µs). However, in some embodiments, the implementation of the amplitude and width of the pulse may differ from the above examples.

Source 110 RF power is a device or system configured to generate signal 122 RF power. Source 110 RF power contains a circuit generating pulses, which contains a circuit designed to control at least one of the amplitude, delay and width of the pulse in the signal 122 RF power. For example, RF power source 110 may include high voltage power sources, solid state or other high voltage/high current switches, transformer networks, LC pulse shaping networks, one or more power storage devices such as capacitors, inductors, and the like. RF power source 110 may also include control logic, as will be described below.

In some embodiments, the RF power source 110 is configured to change the pulse generation of the RF power signal 122 such that the current pulse has one or more of amplitude, delay, and pulse width different from those of the previous pulse. That is, the characteristics of the pulses may differ from pulse to pulse. In some embodiments, RF power source 110 is configured to generate pulses having a discrete number of parameters. For example, the pulse amplitude may be selected from a limited set of two or more amplitudes. However, in other embodiments, the selection may be continuous, variable through analog or digital tuning, substantially continuous in digital steps that are relatively small, or the like. Although amplitude has been used as an example of a parameter that can be changed in a discrete and continuous manner, in other embodiments, other parameters can be changed in a similar manner.

In some embodiments, one or more aspects of the particle power signal 118 and the RF power signal 122 may differ. For example, in some embodiments, the implementation of the temporal response of the signal 122 RF power is different from the signal 118 power particles. In other embodiments, the delay and/or pulse width may differ between the particle power signal 118 and the RF power signal 122. In other embodiments, other aspects of the pulses may differ between the particle power signal 118 and the RF power signal 122. In addition, although certain aspects are described as being different, in some embodiments, several aspects of the pulses may differ between the particle power signal 118 and the RF power signal 122.

Accelerating structure 104 is configured to accelerate particle beam 114 in response to RF signal 120 to generate accelerated beam 116. For example, accelerating structure 104 may be a traveling wave (TW), standing wave (SW), hybrid TW-SW design. or another type of resonant structure. Accelerating structure 104 may include multiple electrodes, waveguide structures, and the like, configured to receive an RF signal 120 and apply that signal to particle beam 114 to generate accelerated beam 116.

In some embodiments, particle beam 114 may be a pulsed electron beam. The pulse of electrons is directed towards the accelerating structure 104. The RF signal 120 may be a pulsed RF signal. As a result, an accelerated electron beam 116 with pulses of accelerated particles can be generated and directed at the target 117 to generate x-rays, or it can be used for other purposes. For simplicity, target 117 is not shown in the other figures; however, the accelerated particle beams described herein can also be directed to the target 117. Moreover, in some applications, the target 117 may not be used. For example, the sterilization system may use the accelerated electron beam 116 itself instead of using it to generate x-rays.

In linacs, the pattern of pulses in the accelerated particle beam 116 depends on the input particle beam 114 and the RF signal 120. A given set of pulses of the particle power signal 118 and the RF power signal 122 with a specific time characteristic generates corresponding pulses in the particle beam 114 and the RF signal 120, which , in turn, generate a corresponding pulse in an accelerated particle beam 116 having a specific energy and dose rate. Dose rate is the amount of radiation absorbed per unit time. Some linac systems use common LC networks and converters to generate signals similar to particle power signal 118 and RF power signal 122. A single high voltage power source can charge a bank of capacitors that are part of the LC network and are discharged into the transformer network to generate both signals. After charging the capacitor bank, the output pulse is formed by discharging the capacitors into the transformer network by means of a thyratron. After turning on the thyratron, the capacitors are discharged by the thyratron until discharged. The resulting pulse width depends on the charge of the capacitor and the transformer network, and the delay depends on the control logic. The thyratron is a type of gas-filled tube used as a high power electrical switch and controlled rectifier. Due to the high current or high voltage, solid state switches were not used.

This common source links the timing of the two signals of conventional linac systems. If the timing of one signal changes, the timing of the other signal also changes. You can choose a different energy and dose by changing the charge of the capacitors, and in other systems, different taps of the transformer network may allow different amplitudes. Regardless of this, the time response of the two signals is fixed. That is, the pulse width and delay are the same. Even if the amplitude of one of the signals may change from pulse to pulse, the time characteristic remains dependent. In addition, energy and dose rate combinations were typically set during development, not user-tuned in the field, and followed a set pattern.

Particle power source 106 and RF power source 110 correspond to respective control signals 124 and 126, respectively. Control logic 112 is coupled to particle power source 106 and RF power source 110. Control logic 112 is configured to generate control signals 124 and 126. Control logic 112 may include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a microcontroller, a programmable logic array (PLA), a device such as a user programmable logic controller (PLC), a field programmable gate array (FPGA), discrete circuits, a combination of such devices, and the like. The control logic 112 may contain internal parts such as registers, caches, processing cores, counters, timers, comparators, adders, and the like, and may also contain external interfaces such as address and data bus interfaces, interfaces interrupts, etc. Other interface devices such as logic, memory, communication interfaces, and the like may be part of control logic 112 for connecting control logic 112 to particle power source 106 and RF power source 110 and other components. The operation of control logic 112 will be described in more detail below with reference to FIG. 2A-2H. Although control logic 112 is shown separately from particle power source 106 and RF power source 110, in some embodiments, control logic 112 may be distributed between a separate component, particle power source 106, and RF power source 110 to perform the operations described below. .

In FIG. 1B is a schematic diagram of a tunable linac, in accordance with some embodiments. System 100b may be similar to system 100a. However, in some embodiments, one or both of the particle power source 106 and the RF power source 110 may be powered by the main power source 160. In this case, both the particle power source 106 and the RF power source 110 are powered by the main power source 160; however, in other embodiments, particle power source 106 and RF power source 110 may be powered by other sources, such as a high voltage source.

In this case, two different main power supplies 160a and 160b are shown. In some embodiments, the power supplied to the particle power source 106 is different from the power supplied to the RF power source 110. For example, the main power supply 160b may be configured to supply power with 230 V single-phase alternating current (AC), and the main power supply 160a may be configured to supply power with 400 V three-phase AC. The power supplies 160a and 160b may be the same power supplies or supply the same amount of power, or the like.

Particle power source 106 and RF power source 110 are each configured to generate a respective particle power signal 118 or RF power signal 122 from a respective main power source 160a or 160b, respectively. In particular, particle power source 106 and RF power source 110 are not configured to generate pulses in the respective particle power signal 118 or RF power signal 122 in response to a common high voltage pulse. Instead, the pulse shaping circuit used to generate each of the particle power signal 118 or RF power signal 122 resides in a respective particle power source 106 or RF power source 110.

In FIG. 1C is a schematic diagram of a tunable linac, in accordance with some embodiments. System 100c may be similar to system 100a and 100b. However, in some embodiments, the RF power source 110c includes a high voltage source 162a and the particle power source 106c includes a high voltage source 162b. That is, the RF power source 110c and the particle power source 106c comprise separate high voltage power supplies 162a and 162b.

Each of RF power source 110c and particle power source 106c is configured to generate a respective high voltage RF power signal 122 or particle power signal 118 from an associated high voltage source 162a or 162b. High voltage sources 162a and 162b are configured to receive input power 161a and 161b, respectively. In some embodiments, input power 161a and 161b may come from a main power source, such as main power supplies 160b and 160a shown in FIG. 1B. However, in other embodiments, the input power 161a and 161b may be generated by a common high voltage source. Accordingly, each of the high voltage sources 162a and 162b can be configured to generate a different internal high voltage, charge internal capacitors, and the like associated with generating the associated RF power signal 122 or particle power signal 118.

In FIG. 1D is a schematic diagram of a custom system according to some embodiments. System 100d includes control logic 112, particle power source 106, and RF power source 110 similar to those described herein, such as those shown in FIG. 1A-C. System 100d is configured to similarly output particle power signal 118 and RF power signal 122. Particle power signal 118 and RF power signal 122 are output to system 103. System 103 may include a particle accelerator system; however, in other embodiments, system 103 may include different types of systems. For example, system 103 may be a system in which the particle power source may be time independent of the RF power source.

In FIG. 2A-2H are timing diagrams depicting various signals in a tunable linac, in some embodiments. System 100a in FIG. 1A is used as an example; however, the signals and timing described herein may apply to other embodiments, such as systems 100b and 100c shown in FIG. 1B and 1C. As shown in FIG. 1A and 2A, in some embodiments, message 200 and a corresponding trigger signal 202 may be received by control logic 112 as control signal 128. In some embodiments, message 200 and trigger signal 202 may be transmitted to control logic 112 via a common communication interface, such as one serial interface, parallel interface, etc. However, in other embodiments, message 200 and trigger 202 may be sent on separate interfaces. For example, message 200 may be transmitted over a serial or parallel interface through which data may be transmitted; however, trigger signal 202 is transmitted through a single line, pin, wire, transmission line, differential pair, and the like. Although specific examples of communication channels or interfaces are described above, in another example, the communication channels or interfaces may be different.

Message 200 is a signal that contains indications of the properties of the incoming pulse. For example, message 200 may include an indication of one or more of the amplitude and timing parameters of particle beam 114, RF signal 120, particle power signal 118, RF power signal 122, and the like. A parameter indication can take a number of forms, such as an absolute parameter value, a relative parameter value, a percentage of a given parameter value, a percentage of the maximum parameter value, an index in a lookup table for a parameter, and the like.

In some embodiments, configuration information may be pre-transmitted to control logic 112. For example, the configuration information may include information associating an index with a particular parameter value. For example, index 0 may be associated with a voltage of 20 kV for the RF power signal 122, and index 1 may be associated with a voltage of 40 kV. As a result, message 200 may only contain an index indicating a specific voltage for RF power signal 122.

In response to receiving message 200, control logic 122 may communicate information based on message 200 for the incoming pulse to particle power source 106 and RF power source 110 using control signals 124 and 126, respectively. This information may or may not be in the same form as the information received by control logic 112 . For example, in some embodiments, control logic 112 may forward configuration information for an incoming pulse to particle power source 106 and RF power source 110. In other embodiments, control logic 112 may convert information, such as by converting the desired energy and dose into amplitude and time response parameters for particle power source 106 and RF power source 110. In some embodiments, control logic 112 may convert the information into source specific information, which may then be further converted by particle power source 106 and RF power source 110. For example, control logic 112 may convert the information into indices, which particle power source 106 and RF power source 110 convert into amplitude and time response information.

The trigger signal 202 represents the signal received by the control logic 112 . For example, trigger signal 202 may be a trigger signal received from a larger system, such as a cargo scanning system that includes system 100a. Trigger signal 202 indicates the point in time from which pulses of particle power signal 118 and RF power signal 122 will be generated.

Message 200 and trigger 202 are skewed in time, with the trigger occurring later. This time offset may allow the content of message 200 to be conveyed to different parts of system 100a and/or allow different parts to be prepared for an incoming pulse. For example, one or both of particle power source 106 and RF power source 110 may require time to charge a bank of capacitors, set switches, or perform other operations to prepare for generating the corresponding particle power signal 118 and RF power signal 122 after receiving trigger signal 202. in response to receiving message 200, control logic 112 may communicate with particle power source 106 and RF power source 110 to set parameters for the incoming pulse, e.g. to particle power source 106 and RF power source 110, and the like. In response, particle power source 106 and RF power source 110 may be prepared to generate a respective particle power signal 118 and RF power signal 120.

Control pulses 204 and 206 control the pulses of particle power signal 118 and RF power signal 122, respectively. Control logic 112 is configured to receive trigger signal 202 and, in response, cause control pulses 204 and 206 to be generated. 110 RF power. However, as will be described below, control of the entire system 100a may be distributed among different subsystems, with message and trigger information being transmitted from the control logic 112 to these subsystems. For example, control logic 112 may receive initial configuration information, which is then separated and transmitted to particle power source 106 and RF power source 110.

Upon receipt of, and in response to, trigger signal 202, control pulses 204 and 206 are generated. In some embodiments, control pulses 204 and 206 may be generated as quickly as possible in response to trigger signal 202. be generated after the delay. In this case, the control pulses 204 and 206 are generated after the delay T1. Control pulses have a pulse width of T2. As shown, control pulses 204 and 206 have the same delay T1 and pulse width T2; however, as will be discussed below, the delay and pulse width may differ.

Although the trigger signal 202 is depicted as a pulse, in some embodiments the trigger information is conveyed by the edge of the trigger signal 202. In this case, the edge is a rising edge, but in other embodiments, the edge may be a falling edge. Also, although the trigger 202 is depicted as having a specific width, the width may be different in other embodiments. For example, trigger signal 202 may have a width that is greater than a threshold value. Trigger signal 202 can be processed to filter out false trigger signals. The threshold width may be used as a criterion for determining whether trigger signal 202 is a valid trigger signal. Delay T1 may allow time to determine if trigger signal 202 is a valid trigger signal before triggering control pulses 204 and 206 to be sent.

As shown in FIG. 1A and 2B, multiple messages 200 and triggers 202 may be received in some embodiments. In this example, two messages 200-1 and 200-2 are received. Upon receipt of each message 200, a corresponding trigger signal 202 is received. In this case, trigger signal 202-1 triggers the sending of control pulses 204-1 and 206-1 based on message 200-1. Similarly, trigger signal 202-2 triggers control pulses 204-2 and 206-2 to be sent based on message 200-2. In this case, the control pulses 204-1, 204-2, 206-1 and 206-2 have the same delay T1 and the same pulse width T2. Each of messages 200-1 and 200-2 may set the same parameters. In other embodiments, message 200-1 may specify parameters and message 200-2 indicates that the last set of parameters should be used.

Messages 200 and/or triggers 202 may be separated in time by an adjustable period. In some embodiments, the resulting control pulses 206 may appear at a controlled pulse rate. Thus, the sequence of control pulses 206 can be separated in time by a period reciprocal of the pulse repetition rate. For a given sequence of control pulses 206, the period between pulses 206 may be substantially the same. However, in other embodiments, the period between pulses 206 may vary between groups of pulses or individual pulses.

Message 200-2 is depicted as later in time than trigger signal 202-1 and control pulses 204-1 and 206-1. For example, in some embodiments, the message delay 200-2 may be used to process data received by the system containing system 100a. However, in other embodiments, the timing may be different. For example, message 202-2 may be transmitted during the passage of trigger signal 202-1 and control pulses 204-1 and 206-1.

As shown in FIG. 1A and 2C, the timing may be similar to that shown in FIG. 2B. However, message 200-3 indicates that although the delay may be the same T1, the pulse width is a different time T3. For example, message 200-3 may indicate a relative increase in T3 pulse width, a different absolute T3 pulse width, a different mode having a T3 pulse width, and the like. Regardless of this, after triggering the sending of the pulse by the trigger signal 202-3, a different pulse width T3 is used. Thus, the pulse width can vary from pulse to pulse. Although only two pulses and associated triggers are shown, the pulse width may change for each successive trigger and associated pulse. Several successive triggers and associated pulses may have the same parameters, several different parameters, or all different parameters.

As shown in FIG. 1A and 2D, the timing may be similar to that shown in FIG. 2C. However, message 200-4 includes a different T4 pulse delay for control pulse 206-4. In this case, the message 200-4 contains an indication of a different delay of the T4 pulse. Another T4 pulse delay may be conveyed in message 200-4 in various ways, as described above. Although a different delay was used for drive pulse 206-4 as an example, the delay may be different for drive pulse 204-4 or different for both drive pulses 204-4 and 206-4. That is, one or both of the control pulses 204-4 and 206-4 may have a different pulse delay T4. Moreover, the delays of the control pulses 204-4 and 206-4 may be different from each other, in addition to being different from the delay T1.

In the various timing diagrams described above, the pulse width and delay for control pulses 204 and 206 have been used as examples. In other embodiments, any combination of pulse width and delay for control pulses 204 and 206 may be used, with some being different and others being the same between the current control pulses 204 and 206 and the previous control pulses 204 and 206. Also, although the difference is described with respect to two successive pulses, there may be various differences between each and any of the pulses, whether they are identical or similar.

As shown in FIG. 1A and 2E, the timing may be similar to that shown in FIG. 2B. In some embodiments, the amplitude of the signal or signals indicated in message 200 may differ from pulse to pulse. Although the time characteristic shown in FIG. 2B is used as an example, the amplitude or amplitudes that change may change as in the other timing examples shown in FIG. 2C and 2D, or other timing changes may be made.

Control pulses 204-1 and 204-2 are associated with power pulses 118-1 and 118-2 of particle power signal 118, respectively. Similarly, control pulses 206-1 and 206-2 are associated with power pulses 122-1 and 122-2 of RF power signal 122, respectively. The first message 200-1 may set the amplitudes for the power pulses 118-1 and 122-1. In response to the trigger signal 202-1, the amplitudes are set in power pulses 118-1 and 122-1, respectively.

The second message 200-2 specifies a different amplitude for both power pulses 118-2 and 122-2. As a result, in response to the trigger signal 202-2, the amplitudes are set accordingly. While increasing the amplitude of both power pulses 118 and 122 has been used as an example, the amplitude of any particular power pulse may not change, may decrease, and may vary by different amounts.

As described above, the timing and amplitude of the power pulses 118 and 122 may differ for each power pulse 118 and 122 from pulse to pulse, and the power pulses 118 and 122 may differ from each other. In some embodiments, the amplitude of one or more of the power pulses 118 and 122 may vary within a pulse. Voltage, pulse width, pulse delay, and other characteristics of the pulses may be independent and/or different. As a result, the RF signal 120 and the particle beam 114 may have similar respective characteristics, which affects the accelerated particle beam 116. In addition, although two pulses were used as an example, in other embodiments, the implementation of the sequence of pulses with different parameters may consist of three or more pulses.

As shown in FIG. 2F, in some embodiments, a single message may be associated with multiple triggers. For example, the time characteristic in Fig. 2E may be similar to that shown in FIG. 2B. However, a single message 200-1 is used to set the properties of the pulses that are triggered in response to triggers 202-1 and 202-2. In this example, the properties are the same, since the subsequent trigger signal 202-2 can only trigger the sending of those pulses that have the latest properties at the moment. However, in other embodiments, the implementation of the properties may differ according to the information specified in the message. For example, message 200-1 may contain information for two or more different subsequent pulses. In another example, message 200-1 may specify how the pulses in subsequent triggers will change, such as an increase or decrease in amplitude or timing, a pattern for changes, and the like. After each trigger signal, particle power source 106 and RF power source 110 may be reset to generate another pulse in preparation for the next trigger signal 202. For example, control logic 112 may begin resetting particle power source 106 and RF power source 110 after generating control pulses. 204-1 and 206-1 to prepare for trigger 202-2. In some embodiments, associating a single message with multiple triggers may provide a higher pulse rate because message 200 is not transmitted for every pulse.

As shown in FIG. 2G, the timing may be similar to that shown in FIG. 2B. However, messages 200-1 and 200-2 that define the associated pulses are received prior to the trigger 202-1 for the first of the pulses. The sending of the second pulse may be initiated in response to the trigger signal 202-2, as determined by message 200-2. Accordingly, multiple pulses may be passed to control logic 112, which then causes associated control pulses 204 and 206 to be sent in response to the respective trigger signal 202.

Regardless of how message 200 and trigger 202 are associated, in some embodiments, each trigger 202 results in a pulse being generated. Message information 200 may be transmitted as described herein at such a rate that trigger signal 202 may generate from less than 30 to about 1000 pulses per second or more.

As shown in FIG. 2H, the time response may be similar to that shown in FIG. 2A. However, the initial configuration information and transmission of pulse information are also shown. In some embodiments, at an earlier time, information 210 is passed to control logic 112. This information 210 includes configuration information for the control logic, particle power source 106, RF power source 110, and the like.

In response to information 210, control logic 112 may communicate system-specific information to various subsystems. For example, particle source information 212 may be transmitted to particle power source 106, and RF source information 214 may be transmitted to RF power source 110. Each of the information 212 and 214 may include system specific information such as timing information, amplitude information, lookup tables, calibration information, and the like, as described above.

Although the information 210 is depicted as a single packet of information, the transmission of the information 210 may be spread over time, transmitted in a sequence of operations, and the like. Similarly, the system-specific information 212 and 214 may also be transmitted in a variety of ways. In some embodiments, information 210, 212, and 214 is transmitted after system 100a is turned on, but before pulses are generated. However, in other embodiments, information 210, 212, and 214 may be transmitted at any time, whereby various subsystems, such as particle power source 106 and RF power source 110, have the information to properly respond to message 200 and trigger 202, including transmission immediately prior to message 200 and trigger 202. Moreover, although transmission of information 210, 212, and 214 is depicted as being performed in sequence with message 200 and trigger 202, in some embodiments, transmission of information 210, 212, and 214 may occur while generating pulses. . For example, as will be described below, in some embodiments, multiple communication channels may connect control logic 112 to other subsystems. Message 200, trigger 202, and information 210, 212, and 214 may be simultaneously transmitted over these communication channels.

Although the transmission of information to particle power source 106 and RF power source 110 has been used as examples, in other embodiments, additional information may be transmitted to other subsystems. For example, information may be sent to a frequency control system for RF source 108, as described below. Moreover, in some embodiments, information for particle power source 106 and information for RF power source 110 may be transmitted together. For example, control logic 112 may pass information for particle power source 106 and RF power source 110 to the modulating subsystem, which then passes that characteristic information to particle power source 106 and RF power source 110.

In some embodiments, by having independent particle power source 106 and RF power source 110, the time response can be changed as described above. Moreover, in some embodiments, both the timing and the amplitude can be changed. This provides independent control of the energy and dose rate of the resulting output pulse in the accelerated particle beam 116 . For example, the user can set the energy to 4 MB and change the dose as desired. The energy can be set for the pulse train by setting the parameters of the RF power source 110, but the timing and/or amplitude of the particle power source 110 can be changed to change the dose or dose rate. In a specific example, during a vehicle scan, the dose rate can be substantially reduced by scanning the part of the vehicle in which the vehicle operator is located. The dose rate may be higher for pulses when scanning other parts of the vehicle containing the load. For example, a reduced dose rate may vary from 0.01 to 0.20 rad/min at a particular pulse rate, while a higher dose rate may vary from 1 rad/min to 30 rad/min at the same pulse rate. As a result, the vehicle operator may not need to leave the vehicle during the scan, which increases throughput. In addition, the user may wish to change the energy level, such as switching between 4 MB, 5 MB, 6 MB, and so on. The independence of the particle power source 106 and the RF power source 110 allows this operation, including changing the energy and then changing the dose for that energy. In one example, the flexibility of changing energy and dose rate can provide better material discrimination (MD) than scanning.

Accordingly, the user may use the control logic 112 to adjust and select from a discrete number to an arbitrary number of modes with various combinations of dose and energy. In some embodiments, multiple modes may be set, but only a subset is transmitted to system 100a, as described above. If a different set of available modes is desired, a different subset may be provided to system 100a as described above. The last subset may or may not overlap with the previous subset. While a subset of modes has been used as an example, in some embodiments, configuration information for all possible modes may be communicated to system 100a as described above.

The independence of the particle power source 106 and the RF power source 110 allows one design to operate similarly to several previous designs. In addition, it is not required to know specific combinations of dose and energy when ordering system 100a. If the desired dose and energy combinations are changed during the design process by the system integrator, no other system is required as long as the new dose and energy combinations are within the configurability of system 100a. The user can change the operating conditions as desired.

In FIG. 3A-3C are schematic diagrams of a trigger distribution system in a tunable linac, in accordance with some embodiments. As an example, the system 100a shown in FIG. 1A; however, the trigger distribution system 300a may be used in other embodiments, such as those shown in FIG. 1B and 1C, etc. In FIG. 4A-4B are timing diagrams of signals in a trigger distribution system in a tunable linac, in accordance with some embodiments.

As shown in FIG. 1A, 3A, and 4A, the trigger distribution system 300a includes first, second, and third control logic 302, 304, and 306 coupled to the trigger bus 311. Control logic 302 may be part of control logic 112. Control logic 304 may be part of a particle system 305 comprising a particle source 102 and a particle power source 106 . Control logic 306 may be part of an RF system 307 comprising an RF source 108 and an RF power source 110. Although particle system 305 and RF system 307 are the only systems depicted with a similar arrangement, in other embodiments, trigger distribution system 300a may include other systems coupled to trigger bus 311.

Each of the control logic circuits 302, 304, and 306 may comprise a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a microcontroller, a programmable logic array (PLA), a device such as a user programmable logic controller (PLC) field-programmable gate array (FPGA), discrete circuits, a combination of such devices, and the like. Each of the control logic 302, 304, and 306 may include internals such as registers, caches, processing cores, counters, such as counters 350, 352, and 354, timers, comparators, adders, and the like, as well as may contain external interfaces such as address and data bus interfaces, interrupt interfaces, and the like. Other interface devices such as logic, memory, communication interfaces, and the like may be part of each of the control logic 302, 304, and 306 to connect the control logic 302, 304, and 306 to the particle power source 106 and 110 RF power, internal components of these sources 106 and 110 and/or other components. Moreover, although particle system 305 and RF system 307 are shown with the same control logic 304 and 306 respectively, in some embodiments the systems may be subdivided into multiple systems, each with its own control logic connected to trigger bus 311.

Trigger input 308 is an input to control logic 302 through which trigger signal 400 from a user can be received. Trigger signal 400 may be received from a larger system that includes system 300a. For example, trigger signal 400 may be generated by a user interface system of a larger system. Regardless of its source, as described above, trigger 400 may be received in a number of ways through a number of interfaces. In some embodiments, trigger input 308 is a single input, a line, a pin, a differential input, or the like.

The trigger bus 311 can take a number of forms. For example, trigger bus 311 may be an electrical connection between the trigger output of control logic 302 and the trigger input of control logic 304 and 306. In other embodiments, the trigger bus 311 may comprise multiple lines, such as one for each downstream control logic, such as control logic 304 and 306.

The control logic 302 is configured to receive a trigger signal 400 and generate another trigger signal 406 on the trigger bus 311 in response to the trigger signal 400. The second trigger signal 406 has a delay with respect to the trigger signal 400 in the amount of a configurable number of counter cycles of the control logic 302 . For example, control logic 302 may include an oscillator, such as a circuit based on a crystal oscillator. This oscillator can be used to cycle the counter of control logic 302 on. Control logic 302 may be configured to latch the state of the counter while receiving the rising edge of trigger signal 400. Control logic 302 may be configured to output trigger signal 406 after a configurable number of cycles of that counter has been reached. In this case, the time T5 represents the delay.

Signal 402 represents the time indicated by the state of counter 350 relative to trigger 400. Variability 408 represents the uncertainty in the value of counter 350 due to factors such as oscillator stability, logic gate delays, and counter cycle time. Trigger signal 406 is generated based on the value of counter 350 and the configurable number of cycles of counter 350. Thus, trigger signal 406 has an uncertainty based on signal 402 uncertainty and additional factors such as oscillator stability, logic gate delays, and counter 350 cycle time. As a result, trigger signal 406 causes a delay T5 relative to trigger signal 400 with uncertainty 410.

In addition to generating trigger signal 406, control logic 302 may be configured to execute an interrupt handler in response to trigger signal 400. Times T6 and T7 represent the minimum and maximum expected processing time to complete execution of the interrupt handler. The difference between the times T6 and T7 may be greater than the uncertainty 410. The time T5 is greater than the maximum expected processing time for the interrupt handler, that is, greater than the time T7. As a result, the appearance of the trigger signal 406 is based on the properties of the oscillator, and not on when the processor can complete the execution of the interrupt routine. In other words, the delay in generating the trigger signal 406 may mask larger uncertainties in the control logic 302, resulting in less uncertainty. In a specific example, the desired delay may be 10 µs +/- 2 µs. However, the termination uncertainty of the interrupt routine can be +/- 3 µs. By hiding the uncertainty of the interrupt handler, higher accuracy can be achieved.

As shown in FIG. 1A, 3A, and 4B, control logic 302 is coupled to trigger bus 311. Two trigger signals 400-1 and 400-2 are shown. Using trigger signal 406-1 as an example, control logic 302 is configured to generate a corresponding trigger signal 406-1 on trigger bus 311 as described above. The control logic 304 and 306 are each configured to receive a trigger signal 400-1 and generate a trigger signal 410-1 or 412-1, respectively, in response. Each of these triggers 410-1 and 412-1 can be generated similarly to trigger 406. That is, the counter 352 and 354 of the associated control logic 304 and 306 is used in generating triggers 410-1 and 412-1.

Triggers 410-1 and 412-1 represent signals at control interfaces 310 and 312 of control logic 304 and 306, respectively. Initiating signals 410-1 and 412-1 and control interfaces 310 and 312 are provided by way of example only. Although only one control interface is depicted for each of the control logic 304 and 306, in other embodiments, one or both of them may have more than one control interface 310 or 312 and may be configured to send more than one corresponding trigger signal 410-1 or 412-1. Although signals 410 and 412 are referred to as trigger signals, the signals may be control pulses as described above.

As described above, the particle system 305 may include a particle power source 106 and a particle source 102. In response to the trigger signal 410-1, the particle power source 106 is configured to generate a particle power signal 118. The particle source 102 is configured to generate a particle beam 114 in response to a particle power signal 118 . Similarly, the RF system 307 may include an RF power source 110 and an RF source 108. In response to the trigger signal 412-1, the RF power source 110 is configured to generate an RF power signal 122. The RF source 108 is configured to generate an RF signal 120 in response to the RF power signal 122. Accordingly, particle beam 114 and RF signal 120 to generate accelerated particle beam 116 can be triggered in response to common trigger signal 400-1, whereby other trigger signals are distributed by timing system 300a.

The operation performed in response to the trigger signal 400-2 may be similar to that described in relation to the trigger signal 400-1. However, as described above, the pulse parameters can be changed. Accordingly, the timing of triggers 410-2 and 412-2 may differ from triggers 410-1 and 412-1, and system operation may also differ.

As shown in FIG. 1A, 3B, 4A, and 4B, trigger distribution system 300b may include additional communication channels between control logic 302, 304, and 306. In this case, two communication channels 360 and 362 are shown; however, in other embodiments, only one or more than two communication channels may be used. Communication channels 360 and 362 may include any communication channel that allows control logic 302, 304 and 306 to transmit information. For example, communication links 360 and 362 may include serial links, parallel links, controller area network (CAN) bus, integrated circuit interconnect (I2C) bus, Modbus, Ethernet, and the like.

The control logic 304 and 306 may include a memory 356 and 357 for configuration information 358 and 359. In some embodiments, configuration information 358 and 359 may be transmitted via communication channel 360. For example, the configuration information 358 may comprise a look-up table (LUT) containing a relationship of index, pulse width, pulse delay, and pulse amplitude of the particle system 305. The configuration information 358 may contain several similar entries to determine several other potential impulses of the particle system 305. Similarly, the configuration information 359 may comprise a look-up table (LUT) containing the relationship of the index, pulse width, pulse delay, and pulse amplitude of the RF system 307. The configuration information 359 may contain several similar entries to identify several other potential pulses of the RF system 307.

Although the storage of configuration information 358 and 359 has been described using LUTs, other methods may be used in other embodiments. For example, configuration information 358 and 359 may contain parameters for equations defining the pulse width, pulse delay, and pulse amplitude of the respective system.

In some embodiments, different types of information may be transmitted over different communication channels 360 and 362. In some embodiments, communication channel 360 may be a higher rate communication channel, while communication channel 362 may be a lower rate communication channel. The time dependent information may be sent over the higher rate link 360 while the configuration information is sent over the lower rate link 362 . For example, configuration information 358 and 359 may be transmitted to particle system 305 and RF system 307, respectively, over a lower rate link 362. However, information about the incoming pulse can be transmitted over the communication channel 360 at a higher transmission rate. In a specific example, at a rate of 500 pulses per second, information about an incoming pulse, configuration of various systems such as particle system 305 and RF system 307, pulse initiation, and the actual pulse itself can be transmitted in less than 2 milliseconds (ms). The high speed link 360 in this example would need to be able to transmit information about an incoming pulse in a fraction of that time to allow time for other pulse related operations.

As shown in FIG. 3C, in some embodiments, trigger distribution system 300c may include an adjustable delay circuit. The adjustable delay circuit is a circuit configured to delay and/or change the timing of the input pulse. Examples of adjustable delay circuits will be described below.

The trigger distribution system 300c includes control logic 302, 304, and 306 similar to those described with reference to FIG. 3A and 3B. However, control logic 302, 304, and 306 comprise adjustable delay circuits 350c, 352c, and 354c, respectively. Adjustable delay circuits 350c, 352c, and 354c may include counters, logic circuits, registers, and the like that provide adjustable delays, or any other hardware or software capable of providing a variable delay.

In FIG. 5A-5D are schematic diagrams of the input and output circuits of a trigger distribution system in a tunable linac, in accordance with some embodiments. In some embodiments, circuits may be used in a tunable linac control logic, such as control logic 112, 302, 304, 306, 812, and the like, as described herein. As shown in FIG. 5A, in some embodiments, an input circuit for receiving trigger signal 508 may include an oscillator 502, a counter 504, and a register 506. Oscillator 502 is configured to generate a clock signal 514 used to increment the value of counter 504. Counter 504 is configured to output counter value 512 . The trigger signal 508 is used to store the current value 512 of counter 504 in register 506.

In some embodiments, trigger 508 may also cause interrupt circuit 530 to set interrupt flag 532. As a result, the processor can handle an interrupt associated with trigger signal 508. For example, as described above, an interrupt handler can be executed to determine if trigger signal 508 is a valid trigger signal. In some embodiments, the interrupt handler may check the state of the trigger signal 508 to determine if the trigger signal 508 has remained high for a time equal to or greater than a threshold. For example, the status of trigger signal 508 may be checked when the current value of counter 504 is less than the sum of the threshold value and the value of counter 504 stored in register 506. If trigger signal 508 is not in a high state during this time, trigger signal 508 may be discarded. like a false signal.

As shown in FIG. 5B, in some embodiments, the output circuit includes an oscillator 502 and a counter 504. Oscillator 502 and counter 504 may be the same circuit, separate but synchronized circuits, or a combination of similar circuits. Regardless, counter 504 continues to output an incrementing value 512. Configuration register 518 is configured to store value 516. Comparator 520 is configured to compare configuration register value 516 and counter value 512 to generate a comparison result 522.

As shown in FIG. 5A and 5B, when operated upon receipt of trigger signal 508, register 506 may store the current value 512 of counter 504. This value may then be output as stored value 510. A delay value 515, expressed in cycles of counter 504, may be added to stored value 510 adder 513 to generate a value 516. The value 516 may be stored in the configuration register 518 and compared with the current value 512 of the counter 504. As a result, after the counter 504 reaches the value 516, i.e. the sum of the stored value 510 and the delay, an output 522 is generated that triggers an action, such as triggering a pulse of particle power signal 118 or RF power signal 120, or triggering another subsystem.

In some embodiments, a gate circuit, such as an AND gate 550, may be used to produce an input trigger signal 508. The trigger signal 508 may have a pulse width that is greater than the sum of the delay time and the maximum pulse width. After counter 504 reaches value 516, i.e. the sum of stored value 510 and delay, pin 522 turns on gate 550 and trigger signal 508 is converted to generate pin 554. Pin 554 can be used in a manner similar to pin 522 described above. A similar circuit with a different configuration register 518 holding the sum of the original value, delay cycles, and pulse width cycles can be used to generate another comparison result 522 that is used to deactivate output 554.

In some embodiments, circuits, such as those described herein, may be implemented with microcontroller input latch and output compare circuits. In particular, since various control logic circuits, such as control logic circuits 302, 304, and 306, are distributed throughout the system, a microcontroller incorporating such circuitry can reduce or eliminate the need for external trigger distribution circuitry. Each subsystem in the system may contain a microcontroller with input latch and output compare circuits.

Although a microcontroller has been used as an example, other circuits may be used in other embodiments to implement trigger distribution. For example, a programmable logic device, such as a field programmable gate array (FPGA), programmable logic array (PLA), or the like, may be used to implement the trigger distribution scheme. In another example, an application specific integrated circuit (ASIC) may be used to implement a trigger distribution scheme.

As shown in FIG. 1A, 3B, 4B, 5A, and 5B, times T8-T11 represent various delays associated with the configuration registers 518 described above. For example, the value for T8 may be stored in the configuration register 518 or other storage device of the control logic 302. Thus, trigger signal 406 may be generated after a number of cycles according to the value for T8 stored in configuration register 518 after the rising edge of trigger signal 400.

Values for T10 and T11 may be stored in control logic 304 configuration registers 518 for particle system 305, such as stored in memory 356 as part of configuration information 358 or in other control logic 304 registers. Accordingly, control pulse 410 may be activated some number of cycles after the rising edge of trigger signal 406. The delay from the rising edge of trigger signal 400 will be approximately equal to the sum of T8 and T10. Similarly, control pulse 410 may be deactivated T11 cycles after the rising edge of trigger signal 406, or T8+T11 cycles after the rising edge of trigger signal 400. The values for T9 and T11 may likewise be stored in control logic 306 of RF system 307, such as stored in memory 357 as part of the configuration information 359 or in other registers of the control logic 306, and the control pulse 412 may be generated accordingly. Although the value of T11 has been used as an example of the common end of control pulses 410 and 412, in other embodiments, the values may differ for control pulses 410 and 412.

The values T8-T11 are used to synchronize control pulses 410 and 412. In some embodiments, the value of T8 may be passed to control logic 304 and/or 306. Control logic 304 and/or 306 may obtain the absolute delay or pulse width from message 200. Using the stored value of T8, appropriate values for T9-T11 may be calculated. In other embodiments, the start difference for values T9-T11 may be embedded in the configuration information passed to control logic 304 and 306. Thus, control logic 304 and 306 may use the exact value that is already agreed upon as the current value of T8.

In some embodiments, the implementation of the value of T11 or similar values that determine the deactivation of the control pulses 410 and 412 may be excluded. As described above, trigger signal 406 and control pulses 410 and 412 may be gate-converted versions of trigger signal 400 and trigger signal 406, respectively. Thus, when trigger signal 400 is deactivated, trigger signal 406 is also deactivated, and therefore control pulses 410 and 412 are deactivated.

By generating trigger signals and control pulses as described herein, a more accurate timing response for control of the pulses can be generated, resulting in an accelerated particle beam 116 . As described above, the uncertainty in the trigger or control output may be approximately equal to the sum of the cycle of the oscillator 502 and the logic gate delays, changes in such delays, and the like. It can be much smaller than the uncertainty in a software based approach that uses an interrupt handler. In some embodiments, since the particle power signal 118 and RF power signal 122 are not generated from a common power pulse, the relative timing of the pulses may depend on the precise distribution of the trigger signal or control pulses across the particle power source 106 and the RF power source 110.

In some embodiments, the implementation of the timing of the pulses can be adjusted using an adjustable delay circuit. The chains in Fig. 5A and 5B are examples of some adjustable delay circuits. As shown in FIG. 5, adjustable delay may be implemented in other ways in adjustable delay circuits such as adjustable delay circuits 350c, 352c, and 354c in FIG. 3C. In some embodiments, the trigger signal 508 may be delayed by multiple delay elements 511. The delay elements 511 may be cascaded to generate trigger signals with multiple delays, such as trigger signals 508'-508'''' with delays.

Delay elements 511 may contain a number of chains. In some embodiments, the delay element 511 may include a transmission line configured to delay the input signal for a certain amount of time. In other embodiments, the delay element 511 may include circuit elements, such as counters, logic gates, flip-flops, registers, and the like, configured to count the number of cycles after receiving an input signal and before outputting a signal.

In some embodiments, the delay on each delay element 511 may be the same. In other embodiments, the delay on one or all of the delay elements 511 may be different.

Logic circuit 560 is configured to generate output 522 based on one or more trigger signals 508-508'''' and control signal 564. Logic circuit 560 may include a logic device configured to selectively combine one or more trigger signals 508-508' ''' to generate output signal 522. As a result, a pulse with adjustable delay and/or adjustable pulse width can be generated as output signal 522 and used as described herein.

In FIG. 5D depicts an example of logic circuit 560 shown in FIG. 5C. Logic circuit 560 is implemented as a delay line in the form of a coaxial cable with taps, which is designed to receive two sets of control signals 564-1 and 564-2. Each of the control signals 564-1 and 564-2 includes control signals sufficient to cause the respective multiplexer 562 to select one of the trigger signals 508-508'''' as the output trigger signals 509-1 and 509-2. The trigger outputs 509-1 and 509-2 are combined by an inverter 566 and an AND gate 568 to generate an output signal 522 having a delay and/or pulse width that is adjusted based on the control signals 561-1 and 564-2.

While circuits have been used as an example that can generate a pulse having an adjustable delay and/or pulse width with respect to an input trigger signal, the adjustable delay circuit can take other forms.

Moreover, the generation of the initiating signal and the control pulse described in this document provides the ability to adjust the delay and pulse width. For example, registers such as configuration register 518 may be set to appropriate values to set the delay and pulse width relative to the incoming user trigger 202, described above with reference to FIG. 2A-2H, the trigger signal 406 on the trigger bus 311 as described above with reference to FIG. 3A-3B, etc. Several of these configuration registers 518 provide for setting the delay and pulse width for multiple pulses of multiple subsystems independently and with the ability to change for each pulse.

As described above, in the independent pulse timing embodiments of particle system 305 and RF system 307, there is no longer a single high voltage pulse that is fed into the transformer network to generate particle power signal 118 and RF power signal 122. For example, when particle power source 106 and RF power source 110 each comprise a high voltage power source 162 that is separated from the other to generate coupled pulses, timing information is conveyed in a different manner. Systems 300a, 300b, 300c, and the like. The trigger distributions described herein are examples of how at least some of the timing information can be distributed across different systems.

Although trigger signals 202, 400, etc. described as being generated by an external source, in some embodiments the trigger signals may be generated by an internal source. For example, the operator may define a pulse repetition frequency (PRF). Control logic 112 or the like. may generate a trigger signal 202, 400, or the like. at the specified frequency at the internal level.

While examples of the trigger distribution system have been described above, in other embodiments, the tunable linac system may comprise other trigger distribution systems.

In FIG. 6A is a block diagram illustrating a method of operating a tunable linac, in accordance with some embodiments. At 600, a pulse message is received. The pulse message may be a message similar to the message 200 described above that indicates the parameters for the RF power signal and the particle power signal, for example, the control logic 112 may receive a message over the communication channel with absolute or relative values for the pulse of the RF power source 110 and particle power source 106 .

At 602, the RF power source is tuned. For example, control logic 112 may convey an index, an absolute value, a relative value, and the like. to RF power source 110 based on the pulse message. RF power source 110 may be directly tuned by control logic 112, or may be tuned by control logic in a subsystem, such as control logic 306. Regardless of this, the RF power source 110 can be configured, for example by charging capacitors, setting switch states, and the like, to be ready for a control pulse.

At step 604, the particle power source 106 is configured similarly to the RF power source 110 using the associated control logic 112 and/or 304 based on the pulse message.

At 612, the particle source is excited with the particle power signal. For example, the particle power source 106 may receive a control pulse triggering the pulse in the particle power signal 118 . This energizes the particle source 102 to generate a particle beam 114 .

At step 614, the RF source 108 is excited with the RF power signal 122. Similar to the particle source 102, the RF power source 110 can receive a control pulse that triggers the pulse in the RF power signal 122. Although the particle source excitation in step 612 is depicted prior to the RF source excitation in step 614, the timing of steps 612 and 614 may be as described above with different pulse delays and/or pulse widths.

At 616, the particle beam is accelerated using the RF power signal from the RF source. For example, particle source 102 directs particle beam 114 into accelerating structure 102 in response to particle power signal 118. The RF signal 120 is applied to the accelerating structure 104, which causes the particles in the particle beam 114 to be accelerated.

In FIG. 6B is a block diagram illustrating a method of operating a tunable linac, in accordance with some embodiments. The method in FIG. 6B may be similar to the method of FIG. 6A. However, in some embodiments, at 606, a trigger signal is received. For example, control logic 112 or 302 may receive a trigger signal. In response to this, at step 608, a particle power signal 118 is generated, and at step 610, an RF power signal 122 is generated. As described above, trigger signals can be used by various control logic to generate control pulses used to control particle systems and RF systems.

In some embodiments, the operations described with reference to FIG. 6A and 6B may be repeated. For example, a second pulse message may be received at step 600. RF power source 110 and particle power source 106 may be reconfigured based on the second pulse message at steps 602 and 604. The reconfiguration may be similar or identical to the tuning process described above. As a result, particle source 102 and RF source 108 can be excited with retuned power signals in steps 612 and 614, whereby a pulse of accelerated particle beam 116 is generated in step 616 based on the second pulse message. Although the term "second" is used to describe the next message, the message can be the nth message with several messages in between.

In particular, in some embodiments, the timing initiated by the first burst message may be different from the timing of the second burst message. For example, the timing of the second RF power signal is different from the timing of the first RF power signal, or the timing of the second particle power signal is different from the timing of the first particle power signal. In some embodiments, the implementation of the temporal characteristics of both signals differ from each other. Another timing may be set by adjusting the particle power source and/or the RF power source in steps 602 and 604, for example by passing new delay and pulse width parameters or indications of these parameters as described above.

Similarly, when setting up particle power source 106 and/or RF power source 110 in steps 602 and 604, the amplitude of the second RF power signal is different from the amplitude of the first RF power signal, or the amplitude of the second particle power signal is different from the amplitude of the first particle power signal. In some embodiments, the amplitudes of both signals are different from each other.

In FIG. 7A-7B are block diagrams illustrating methods for distributing a trigger signal in a tunable linac system, in accordance with some embodiments. As shown in FIG. 7A, at step 700, a first trigger signal is received. In some embodiments, the first trigger signal is a trigger signal from a larger system containing a tunable linac system. For example, the user interface system may generate a trigger that is received by logic 112, 302, or the like. management.

In response to the first trigger, at 708, a second trigger is generated having a delay relative to the first trigger by a configurable number of first counter cycles. Accordingly, the delay of the second trigger signal is based on the cycles of the first counter. The second trigger signal may be a trigger signal generated by logic 112, 302 or the like. control, and the counter may be part of this control logic. The second trigger signal may be generated using the circuits described above, have a delay relative to the first trigger signal, be a gated version of the first trigger signal, and the like, as described above. The second trigger signal can be distributed to different subsystems via a trigger bus.

At 710, a third trigger signal is generated in response to the second trigger signal. The third trigger signal has a delay relative to the second trigger signal in the amount of a configurable number of cycles of the second counter. Accordingly, the delay of the third trigger signal is based on the cycles of the second counter. The third trigger signal may be a trigger signal generated by logic 304 or the like. control, and the counter may be part of this control logic. The third trigger signal may be generated using the circuits described above, have a delay relative to the second trigger signal, be a gated version of the second trigger signal, and the like, as described above.

At 712, a particle power signal is generated in response to the third trigger signal. As described above, the particle power source 106 may be configured to generate a particle power pulse having a specific delay, pulse width, and amplitude.

At 714, a particle beam is generated in response to the particle power signal. As described above, a particle power pulse may be generated and applied to a particle source to generate a pulse in the particle beam.

In some embodiments, a third trigger signal may be used to generate a control pulse. When generating a control pulse, the third trigger signal can be used as a control pulse or used to set a delay. The control pulse may be a pulse with an appropriate delay and pulse width relative to the first trigger signal. In some embodiments, a second configurable number of cycles of the second counter is used to generate a control pulse. The second configurable number of cycles of the second counter may determine the pulse width. Thus, both delay and pulse width can be determined by counter cycles.

At 716, a fourth trigger signal is generated in response to the second trigger signal. The fourth trigger signal has a delay relative to the second trigger signal in the amount of a configurable number of cycles of the third counter. Accordingly, the delay of the fourth trigger signal is based on the cycles of the third counter. The fourth trigger signal may be a trigger signal generated by logic 306 or the like. control, and the counter may be part of this control logic. The fourth trigger signal may be generated using the circuits described above, have a delay with respect to the second trigger signal, be a gated version of the second trigger signal, and the like as described above.

At 718, an RF power signal 122 is generated in response to the fourth trigger signal. As described above, RF power source 106 may be configured to generate an RF signal pulse having a specific delay, pulse width, and amplitude.

At 720, an RF signal 120 is generated in response to the RF power signal 122. As described above, a pulse of RF power signal 120 may be generated and applied to RF source 108 to generate a pulse in RF signal 120.

At 722, the particle beam 114 is accelerated in response to the RF signal 120.

In some embodiments, the implementation of the fourth initiating signal may be used to generate a control pulse. When generating a control pulse, the fourth trigger signal can be used as a control pulse or used to set a delay. The control pulse may be a pulse with an appropriate delay and pulse width relative to the first trigger signal. In some embodiments, a second configurable number of cycles of the third counter is used to generate a control pulse. The second configurable number of cycles of the third counter may determine the pulse width. Thus, both delay and pulse width can be determined by counter cycles.

The operations in steps 710 and 716 are depicted in parallel because the generation of the trigger signals and subsequent operations in steps 712, 714, 718 and 720 can be performed in parallel. In particular, the operations may be performed such that the generation of the particle beam at step 714 and the generation of the RF signal at step 720 can be performed in parallel. The generation of the RF signal and the particle beam are based on separate third and fourth trigger signals. The configurable number of cycles of the second counter and the configurable number of cycles of the third counter may be different. As a result, the timing of the third trigger signal and the fourth trigger signal may differ.

As shown in FIG. 7B, in some embodiments, the operation may be similar to that of FIG. 7A. However, in some embodiments, some operations are performed between receiving the first trigger at 700 and generating a second trigger in response to the first trigger at 702. For example, at 702, an interrupt handler is executed. The interrupt handler may be executed by logic 112, 302, or the like. management.

In some embodiments, part of the interrupt handler may be designed to determine if the first trigger signal was a valid trigger signal. For example, at step 704, the first trigger signal may be analyzed by the interrupt handler to determine if it is valid, for example, by measuring the pulse width, determining whether the first trigger signal maintained an active state for a threshold period of time, and so on. . If the trigger signal is not valid, at 706, the trigger signal may be discarded. The subsequent generation of the second trigger signal at step 708 may not be performed.

However, if the first trigger signal is valid at 704, the second trigger signal may be generated at 708. In particular, since the second trigger signal is generated based on a configurable number of counter cycles, the delay of the second trigger signal may represent an isolated uncertainty in the processing of the processing program. interrupts. Thus, the delay of the second initiating signal is greater than the completion time of the interrupt service routine and, otherwise, does not depend on it.

In some embodiments, the operations shown in FIG. 6A and 7A and the like may be combined. For example, the pulse message received at step 600 may be associated with the trigger signal received at step 700. Part of setting the particle power source at step 604 may include determining an adjustable number of cycles of the second counter in response to the pulse message. The RF power source setting portion of step 602 may include determining a configurable number of third counter cycles in response to the pulse message.

In FIG. 8A and 8B are schematic diagrams of frequency control systems in a tunable linac, in accordance with some embodiments. As described above, the amplitude of the RF signal may vary from pulse to pulse and vary in a potentially arbitrary or random manner. Also, with RF sources such as a magnetron, the tuning mechanism may not be able to tune on a pulse-by-pulse basis at pulse rates of 100 to 1000 or more pulses per second. As a result, due to a change or potential change in the amplitude of the RF power signal, one setpoint for the frequency control system for the RF source may be suitable for the first sequence of RF signal amplitudes, but may not be suitable for the second sequence of RF signal amplitudes.

As shown in FIG. 8A, system 800a includes a particle source 102 and an accelerating structure 104 similar to systems such as system 100a, 100b, 100c, and the like described above. System 800a may also have similar components such as particle power source 106 and RF power source 110, but these components are not shown to emphasize the frequency control system of system 800a. System 800a includes an RF source 808, which may be similar to the RF source 108 described above. In addition, system 800a includes an RF system 807 comprising an RF source 808 and an RF frequency control circuit 856 comprising a sensor 854, a feedback circuit 846, and a frequency controller 840 for the RF source 808.

In some embodiments, frequency controller 840 is configured to adjust the frequency of RF source 808. For example, RF source 808 may be a magnetron, and frequency controller 840 may include a tuning motor and tuning core coupled to the magnetron. In another example, RF source 808 may be an electrically tuned source, such as an RF driver, that provides an RF signal to the klystron, and frequency controller 840 may include electrical tuning circuitry for the RF driver. However, in other embodiments, the implementation of the RF source 808 may have a different form and may have a different frequency controller 840.

The RF source is configured to generate an RF signal 120. The sensor 854 is configured to measure portions of the RF signal 120 to generate a feedback signal 844. Sensor 854 may take a number of forms. For example, sensor 854 may include directional couplers, 3 decibel (dB) hybrid couplers, phase shifters, detectors, filters, and the like. Any circuit that can provide a feedback signal 844 that indicates a match between the frequency of the RF signal and the resonant frequency of the accelerating structure 104 can be used as a sensor 854. In some embodiments, the feedback signal 844 includes one or more signals representing the phase shift between the direct and reflected signal of the RF signal or signals 120 as measured by the sensor 854. For example, when the output frequency of the RF source 808 corresponds to the resonant frequency of the accelerating structure 104, the phase relationship between the direct and reflected RF signals may have a particular value. When the RF source 808 becomes incompatible with the accelerating structure 104, the phase relationship changes. Feedback signal 844 may represent this phase shift and may be used to tune RF signal 120.

The feedback loop 846 is configured to receive a feedback signal 844 and a setpoint signal 850. The feedback loop 846 includes any circuit that can combine the feedback signal 844 and the setpoint signal 850 into an error signal 848. For example, the feedback loop 846 may include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a microcontroller, a field programmable gate array (FPGA), a programmable logic array (PLA), a programmable logic device, discrete circuits, a combination of such devices; and the like. The feedback loop 846 may be configured to implement a number of control loops, such as a proportional-integral-derivative (PID) control loop. Sensor 854, feedback circuit 846, and frequency controller 840 form an RF frequency control circuit 856 configured to adjust the frequency of RF source 808. Setpoint signal 850 provides a method for adjusting the setpoint of RF frequency control circuit 856.

System 800a also includes control logic 812. Control logic 812 may be similar to logic 112, 302, 304, 306, and the like. control described above, or part of it. However, the control logic 812 is configured to adjust the RF setpoint signal 850 of the frequency control circuit 856 . In particular, control logic 812 is configured to receive multiple settings for RF source 808 over time. As described above, the settings for RF source 808 may vary from pulse to pulse. These settings may be received in messages 852 received by control logic 812. Control logic 812 is configured to adjust RF signal 120 in response to settings, such as by adjusting the energy of RF signal 120. In addition, control logic 812 is configured to adjust RF setpoint signal 850 of frequency control circuit 856 in response to settings, for example, by adjusting the setpoint signal 850 applied to the feedback circuit 846.

Accelerating structure 104 may include a number of cavity resonators that use a standing wave of RF energy to accelerate a particle beam fed into the resonators by a particle source. The RF signal 120 produced by the RF source 808 must be at the resonant frequency of the resonators in the accelerating structure 104 to create a standing wave so that the particle beam 114 can be accelerated as it passes through the row of resonators. The RF source 808 has a frequency control 840, such as a mechanical tuning core, that is physically rotated in and out to adjust the output frequency of the RF signal 120. The frequency control 840 is used to adjust the frequency of the RF signal 120 to match the frequency of the accelerating structure 104.

In some embodiments, RF source 808 produces a large amount of power and is directed to accelerating structure 104. The efficiency of both of these components can be relatively low, resulting in a large amount of heat being absorbed by both RF source 808 and accelerating structure 104. This heat results in a change the physical dimensions of the RF source 808 and accelerating structure 104, which affects both the output frequency of the RF signal 120 and the resonant frequency of the accelerating structure 104. Due to this effect, the RF frequency control circuit 856 is used to adjust the output frequency of the RF source 808 to ensure that that it corresponds to the resonant frequency of the accelerating structure 104.

If RF source 808 has been operating at a single energy level or with a known repetitive change in energy levels, RF frequency control circuit 856 can be set to a single setting that provides an optimal match between the frequency of RF signal 120 and the resonant frequency of accelerating structure 104 for that fixed operating state. However, as described above, the energy level of the RF signal 120 may be arbitrary. The energy may vary from pulse to pulse in a manner that may be determined solely by the discretion of the user and the overall operating range.

Control logic 812 is configured to use settings for RF source 808 over time to account for changes in settings. As described above, messages 200 may be received that indicate the energy of the RF source 808. The indication may be conveyed in various ways, such as an index in a table, an absolute value, a relative value, and the like. Regardless, energy information is present in messages 200 received by control logic 812.

Although the settings mentioned above were in the context of message 200 received by control logic similar to control logic 112 described above, the source of the settings received by control logic 812 may be different. For example, as described above with reference to FIG. 3A and 3B, information from message 200 may be distributed to various systems, including RF system 307. Thus, the settings may be information that has been transmitted to RF system 307 and/or other system specific to frequency control of RF source 808. .

The control logic 812 is configured to use these settings to adjust the setpoint signal 850. One setting is not used on a one-to-one basis to set the setpoint signal 850. Instead, several settings are used to define the setpoint signal 850. In some embodiments, control logic 812 is configured to maintain a settings history containing the most recent few settings for RF source 808. For example, control logic 812 may maintain a list of the most recent 20 settings for RF source 808.

In response to these settings, the control logic 812 is configured to adjust the RF setpoint 850 of the frequency control circuit 856. Control logic 812 may use a number of methods to adjust setpoint 850. In some embodiments, control logic 812 is configured to implement a majority detection algorithm. The control logic 812 may analyze the setting history to determine if one particular setting has the most settings in history. For example, a number of settings for each mode of operation may be defined. In another example, the settings may be categorized by energy levels. In particular, settings that can be identified as different modes may have the same energy level for RF source 808 but have different settings for particle source 102. They can be classified in the same energy level category. Similarly, settings with the same energy level but different pulse widths can be classified into different energy level categories. Any subdivision of settings into different categories can be done.

Based on the categorized settings, the control logic 812 may be configured to select a category from the energy level categories having the most settings. That is, one category may have most or many of the settings among the categories. This category can be used to define the setpoint signal 850 for the RF frequency control circuit 856. In a specific example, the energy associated with the selected category may be used to determine the setpoint signal 850. This setpoint signal 850 is then applied to the RF frequency control circuit 856 .

Control logic 812 may contain calibration values for a number of different combinations of energy levels and/or pulse widths. These calibration values may represent open loop settings for feedback signal 844 when the frequency of RF signal 120 is optimized for a particular mode involving a combination of energy level, pulse width, and the like. In some embodiments, calibration values may be generated for each potential mode of operation of system 800a, including modes that differ only in parameters associated with particle source 102. In other embodiments, calibration values may be generated that are specific to the parameters of the RF source 808. In other embodiments, calibration values may be generated for different energy levels independent of other parameters such as pulse width or delay.

In a particular example, where the RF signal 120 may have two different energy levels, the history settings can be analyzed to determine which energy setting is present in the most settings. Using a depth of 20 settings as an example, if 11 or more settings are high energy settings, this energy level can be used to determine the setpoint signal 850 for the RF frequency control circuit 856. In some embodiments, if the number of settings of two different energy levels is the same, the highest energy level may be selected to determine the setpoint signal 850. So if the next setting added to the history is a low energy setting and the earliest energy level is a high energy setting, the ratio of high energy to low energy would be 10:10. As a result, the high energy setting will be selected. If the next setting after the 10:10 ratio is another low energy setting and the other high energy setting is removed, the high to low energy ratio will be 9:11. As a result, a low energy setting will be selected.

Although the majority or plurality selection method has been described as a method for determining the energy level for selecting setpoint signal 850, setpoint signal 850 may be determined in other ways. For example, the energy levels of settings in history can be combined with each other to generate a composite energy level. This composite energy level can be used to select the setpoint signal 850, for example by selecting the energy level associated with the calibrated setpoint signal 850 that is closest to the composite energy level, interpolating between the two calibrated setpoint signals 850 using the two energy levels closest to composite energy level, etc.

In other embodiments, energy levels may be combined with weighting factors that increase with energy level. Thus, the selected setpoint signal 850 may be weighted towards higher energy levels, which may have a higher probability of affecting the frequency matching of the RF signal 120 and the resonant frequency of the accelerating structure 104.

In some embodiments, the history depth may be chosen to be long enough to provide some filtering of energy changes, but also short enough to match the desired level of sensitivity. For example, at a pulse repetition rate of 100 pulses per second, a history depth of 20 pulses may be used. Thus, the settings in history are the pulse settings for the last 0.2 seconds. In another example, the history may be configured to be long enough to store one or more complete cycles of a repeating sequence of settings. The history can also be small enough that a full history decision can be made in a shorter amount of time.

In some embodiments, the history may be implemented as a sliding window of the most recent settings. For example, the history can act as a first-come-first-served buffer, where each new setting for the current or incoming pulse is immediately added to the history, and the oldest setting is removed from the history.

In some embodiments, after selecting a particular mode from a previous setting history, the calibration information associated with that mode can be used to set a setpoint of 850. For example, a mode index can be used to view the calibration values for that mode. Control logic 812 then sets a setpoint 850 for that particular calibrated value.

While the setpoint signal 850 selection examples are based on finding the closest match to a single calibrated mode, in other embodiments, calibration values may be generated for mode patterns. For example, a predicted mode change pattern may be applied to system 800a, the frequency of RF signal 120 may be adjusted to the optimum setting, and the pattern may be reused. For several different templates, several calibration values can be generated. As will be described in more detail below, in some embodiments, feedback signal 844 may be sampled. If a mode pattern is detected, the mode having the higher or highest energy may be used as the mode during which the RF frequency control circuit is applied.

In some embodiments, system 800a includes a select-and-hold (S/H) circuit 870. The S/H loop 870 is configured to sample the feedback signal 844 to generate a sampled feedback signal 845 in response to the control signal 851. The feedback loop 846 is configured to use the sampled feedback signal 845. As described above, the RF signal 120 may be pulsed. Feedback signal 844 may only be valid during a pulse of RF signal 120. Control logic 812 may be configured to generate a control signal 851 to activate S/H circuit 870 during the pulse. In some embodiments, control logic 812 may be configured to generate control signal 851 with a pulse width that matches the pulse width of control signal 126 (depicted in FIG. 1A). However, in other embodiments, the pulse width may be different. In some embodiments, the pulse width of the control signal 851 may be fixed, regardless of the mode. However, the pulse delay of the control signal 851 may still vary based on the mode.

In addition, control logic 812 may be configured to change the timing of control signal 851 in response to an indication of the pulse timing of RF signal 120. As described above, the pulse timing delay may vary from pulse to pulse. The delay of the control signal 851 can be changed accordingly. As a result, the sampling of the feedback signal 844 can account for changes in the delay of the RF signal 120.

Moreover, as described above, control logic 812 may select a particular mode based on multiple settings over time to set setpoint 850. In some embodiments, control logic 812 may select one of the modes as the mode during which circuit 856 is activated. frequency control. Control signal 851 can only be activated during pulses of one of the specified modes. Thus, while RF signal 120 may be pulsed, control signal 851 may not be pulsed for each of these RF signal 120 pulses. As a result, RF frequency control circuit 856 may only be activated for pulses associated with a particular mode.

Considering an example with 20 history settings and two modes, when the ratio of the higher energy mode to the lower energy mode is 11:9, the control signal 851 can only be activated when the higher energy mode is pulsed. Control signal 851 will be activated whenever the higher energy mode is pulsed, as long as the higher energy mode is dominant in history. However, after the ratio is changed to 9:11, the control signal 851 will only be activated when the lower energy mode is pulsed.

Although an S/H 870 circuit has been used as an example, in other embodiments, sampling may be performed in other ways. For example, the feedback signal 844 may be continuously sampled in the feedback loop 846 . The feedback loop 846 may use only a portion of the digitized feedback signal 844 corresponding to the desired pulse of the RF signal 120.

In some embodiments, control logic 812 may be configured to retain a default setting. After the pulse train, the state of the RF frequency control circuit 856 may depend on the last mode, or the last mode that was sampled, to adjust the frequency of the RF source 808. In some embodiments, the control logic 812 may be configured to set the setpoint 850 state and the signal state 848 errors, whereby the frequency controller 840 of the RF source 808 is in a known state. As a result, the repeatability of the pulse train can be improved. In some embodiments, after a pulse train, the settings history may be reset to default settings.

As shown in FIG. 8B, system 800b may be similar to system 800a described above. However, in some embodiments, a particular type of sensor 854 or feedback path may be used. In this case, incident and reflected couplers 860 are connected between the RF source 808 and accelerating structure 104. Incident and reflected couplers 860 are configured to provide signals indicative of the applied RF signal 120 and the signal reflected from the accelerating structure 104. Incident and reflected couplers 860 the waves can be implemented with a four-input directional coupler, multiple couplers, and the like. Regardless of this, forward and reverse signals are generated, one of which can be phase-shifted by the phase shifter 862. The two resulting signals enter the 3 dB hybrid quadrature coupler 864.

The output signals 844a and 844b from the 3 dB hybrid coupler 864 enter the feedback loop 846 . The feedback loop 846 may include analog-to-digital converters for digitizing the output signals 844a and 844b. In some embodiments, the digitized output signals 844a and 844b may be used as feedback signal 844; however, in other embodiments, the digitized outputs 844a and 844b may be combined, such as by subtraction, to generate a single feedback signal 844. The amplitudes of these signals, or the combined signal, change as the RF signal 120 moves away from resonance.

Although not shown, other components may be present in system 800b. For example, the output signals 844a and 844b from the 3 dB hybrid coupler 864 may be filtered to remove higher frequency components. In addition, various amplifiers can be provided in the feedback path.

Although a specific example of a method for generating feedback signal 844 or feedback signals 844a and 844b has been described with reference to FIG. 8B, other methods may be used in other embodiments, as described with reference to FIG. 8A.

In FIG. 8C is a schematic diagram of a frequency control system in accordance with some embodiments. In some embodiments, parts of system 800c may be similar to parts of systems 800a and 800b depicted in FIG. 8A and 8B and are implemented as described herein. However, RF system 807c of system 800c is configured to drive RF load 104c to generate output 116c. In some embodiments, RF load 104c may include loads that may have a resonant frequency that may change during operation, such as when different settings are used to control RF system 807c. In a specific example, any circuit, structure, system, or the like having a resonant cavity can be used as RF load 104c.

In FIG. 9 is a block diagram illustrating methods for adjusting the RF source frequency of a tunable linac, in accordance with some embodiments. As an example, system 800a shown in FIG. 8A; however, in other embodiments, the methods may be used in other systems.

At 900, an RF source is used to generate an RF signal in response to a plurality of energy level settings over time. As described above, RF source 808 may operate at multiple settings, which may have multiple energy levels. As a result, RF signal 120 may have multiple energy levels over time.

At 902, the particle beam is accelerated in response to the RF signal. For example, particle beam 114 generated by particle source 102 may be accelerated in accelerating structure 104 in response to RF signal 120 from RF source 808.

At 904, the frequency of the RF source is adjusted in response to the energy level settings. For example, RF frequency control circuit 856 may be used to control the frequency of RF signal 120. Control logic 812 may adjust setpoint 850 in response to various settings, as described above.

As part of the frequency control of the RF source, an indication of the pulse timing of the incoming RF pulse can be taken. For example, as described above, a message 200 may be received containing an indication of the pulse timing of the RF signal 120. Accordingly, the RF pulse timing may be changed for the incoming pulse. The sampling timing of the RF feedback signals in the frequency control circuit 856 for the RF source 808 is changed based on the pulse timing indication.

As part of RF source frequency control, an energy level history can be maintained containing the last few energy level settings to date. For example, as described above, control logic 812 may maintain a history of settings. The frequency of the RF source can be adjusted in response to the history.

As part of adjusting the frequency of the RF source 808, history energy level settings can be categorized according to energy level. Once categorized, the energy level setting category with the most recent energy level settings so far can be selected, and the frequency of the RF source 808 can be adjusted in response to the selected category. For example, control logic 812 may maintain categories, put new settings into categories, remove old settings from categories, and the like. From the categories, the control logic can choose the one with the most number and choose setpoint 850 in response.

As part of RF source frequency adjustment, history energy level settings can be combined into a combined energy level. Alternatively or additionally, history energy level settings may be combined into a combined energy level using weighting factors that increase with energy level. The frequency of the RF source can be adjusted in response to the combined energy level. For example, control logic 812 may combine energy level settings into a combined energy level. This combined energy level may be used by control logic 812 to select a setting for setpoint 850.

Although the operations of the tunable linac system have been described above in the context of specific components, in other embodiments, these operations may be performed by other components.

In FIG. 10 is a schematic diagram of a 2D x-ray imaging system in accordance with some embodiments. The imaging system 1000 includes an x-ray source 1002 and a detector 1010. The x-ray source 1002 may include a tunable linac, as described above. X-ray source 1002 is positioned relative to detector 1010 such that X-rays 1020 passing through sample 1022 and detected by detector 1010 can be generated.

As shown in FIG. 19, some embodiments provide a system comprising: a particle power source 106 configured to generate a particle power signal 118; a radio frequency (RF) power source configured to generate a 120 RF power signal; wherein the temporal response of the RF power signal 120 is different from the temporal response of the particle power signal 118 .

In some embodiments, the system further comprises a particle source 102 configured to generate a particle beam 114 in response to a particle power signal 118; An RF source 108, 808 configured to generate an RF signal in response to the RF power signal 120; and an accelerating structure 104 configured to accelerate the particle beam 114 in response to the RF signal.

In some embodiments, the RF power source 110 is configured to generate an RF power signal 120 having a voltage independent of the particle power signal 118.

In some embodiments, the RF power source 110 is configured to generate an RF power signal 120 having a time response independent of the particle power signal 118.

In some embodiments, the pulse width of the RF power signal 120 is different from the pulse width of the particle power signal 118.

In some embodiments, the pulse delay of the RF power signal 120 is different from the pulse delay of the particle power signal 118.

In some embodiments, the particle power source 106 comprises a first high voltage source 162b configured to generate a first high voltage due to the main power supply and configured to generate a particle power signal 118 in response to the first high voltage; and the RF power source 110 comprises a second high voltage source 162a configured to generate a second high voltage due to the main power supply and configured to generate an RF power signal 120 in response to the second high voltage.

In some embodiments, the system further comprises control logic 112, 302, 304, 306, 812 coupled to particle power source 106 and RF power source 110, wherein control logic 112, 302, 304, 306, 812 is configured to: receive impulse message; receiving an initiating signal; activating the particle power source 106 in response to the pulse message and trigger signal; and activating the RF power source 110 in response to the pulse message and the trigger signal.

In some embodiments, the system further comprises control logic 112, 302, 304, 306, 812 coupled to particle power source 106 and RF power source 110, wherein control logic 112, 302, 304, 306, 812 is configured to: receive several impulse messages; receiving a plurality of trigger signals, each trigger signal being associated with a respective one of the pulse messages; and for each trigger signal: activating particle power source 106 in response to the trigger signal and the corresponding pulse message; and activating the RF power source 110 in response to the trigger signal and the corresponding pulse message.

In some embodiments, for the first trigger signal and the second trigger signal of the trigger signals: the first trigger signal and the second trigger signal are sequential; the pulse message corresponding to the first trigger signal contains an indication of the first amplitude of one of the particle power source 106 and the RF power source 110; the pulse message corresponding to the second trigger signal contains an indication of the second amplitude of one of the particle power source 106 and the RF power source 110; and the first amplitude is different from the second amplitude.

In some embodiments, for the first trigger signal and the second trigger signal of the trigger signals: the first trigger signal and the second trigger signal are sequential; the pulse message corresponding to the first trigger signal contains an indication of the first time characteristic of one of the particle power source 106 and the RF power source 110; the pulse message corresponding to the second trigger signal contains an indication of the second time characteristic of one of the particle power source 106 and the RF power source 110; and the first timing is different from the second timing.

In some embodiments, for the first trigger signal, the second trigger signal, and the third trigger signal of the trigger signals: the first trigger signal, the second trigger signal, and the third trigger signal are sequential; the pulse message corresponding to the first trigger signal contains an indication of the first time characteristic or amplitude of one of the particle power source 106 and the RF power source 110; the pulse message corresponding to the second trigger signal contains an indication of the second time characteristic or amplitude of one of the particle power source 106 and the RF power source 110; the pulse message corresponding to the third trigger signal contains an indication of a third time characteristic or amplitude of one of the particle power source 106 and the RF power source 110; and the first timing or amplitude is different from the third timing or amplitude.

Some embodiments provide a system comprising: a particle power source 106 configured to receive a first AC power and a first drive signal, and generate a particle power signal 118 from the first AC power based on the first drive signal; a radio frequency (RF) power source configured to receive the second AC power and the second drive signal, and generate an RF power signal 120 from the second AC power based on the second drive signal; and a control logic 112, 302, 304, 306, 812 configured to generate a first control signal and a second control signal.

In some embodiments, the system further comprises a particle source 102 configured to generate a particle beam 114 in response to a particle power signal 118; An RF source 108, 808 configured to generate an RF signal in response to the RF power signal 120; and an accelerating structure 104 configured to accelerate the particle beam 114 in response to the RF signal.

In some embodiments, for at least one set of the first drive signal and the second drive signal, the amplitude of the RF power signal 120 is different from the amplitude of the particle power signal 118, or the timing of the RF power signal 120 is different from the timing of the particle power signal 118.

In some embodiments, for at least one set of the first drive signal and the second drive signal, the timing of the RF power signal 120 is different from the timing of the particle power signal 118.

Some embodiments provide for a method including: receiving a burst message; setting a radio frequency (RF) power source to output a 120 RF power signal based on the pulse message; and setting the particle power source 106 to output the particle power signal 118 based on the pulse message.

In some embodiments, the implementation of the method further includes the excitation of the source 102 particles signal 118 particle power; driving the RF source 108, 808 with the RF power signal 120; and accelerating particle beam 114 from particle source 102 using RF source 108, 808.

In some embodiments, the method further comprises: receiving a trigger signal associated with the burst message; generating a 120 RF power signal in response to the trigger signal; and generating a particle power signal 118 in response to the trigger signal.

In some embodiments, the RF power signal 120 is referred to as the first RF power signal 120 and the particle power signal 118 is referred to as the first particle power signal 118, the method further comprising: receiving a second pulse message; reconfiguring the RF power source 110 to output a second RF power signal 120 based on the second pulse message; reconfiguring the particle power source 106 to output a second particle power signal 118 based on the second pulse message; wherein the second RF power signal 120 is different from the first RF power signal 120 or the second particle power signal 118 is different from the first particle power signal 118 .

In some embodiments, the method further comprises excitation of the particle source 102 with a second particle power signal 118; and driving the RF source 108, 808 with the second RF power signal 120.

In some embodiments, the method further includes optionally excitation of the particle source 120 with the particle power signal 118; optionally driving the RF source 108, 808 with the RF power signal 120; optionally, excitation of the particle source 120 with a second particle power signal 118; optionally driving the RF source 108, 808 with a second RF power signal 120; and optionally accelerating particle beam 114 from particle source 102 using RF source 108, 808.

In some embodiments, the timing of the second RF power signal 120 is different from the timing of the first RF power signal 120, or the timing of the second particle power signal 118 is different from the timing of the first particle power signal 118.

In some embodiments, the amplitude of the second RF power signal 120 is different from the amplitude of the first RF power signal 120, or the amplitude of the second particle power signal 118 is different from the amplitude of the first particle power signal 118.

In some embodiments, the implementation of the temporal response of the signal 120 RF power is different from the temporal response of the signal 118 power particles.

Some embodiments provide a system comprising: first control logic 112, 302, 304, 306, 812, configured to receive a first trigger signal and generate a second trigger signal in response to the first trigger signal, wherein the second trigger signal is delayed relative to the first trigger signal. a signal in the amount of a configurable number of counter cycles of the first control logic 112, 302, 304, 306, 812; second control logic 112, 302, 304, 306, 812, configured to receive a second trigger signal and generate a third trigger signal in response to the second trigger signal, wherein the third trigger signal has a delay relative to the second trigger signal in the amount of a configurable number of second trigger cycles. control logic 112, 302, 304, 306, 812; third control logic 112, 302, 304, 306, 812, configured to receive a second trigger signal and generate a fourth trigger signal in response to the second trigger signal, wherein the fourth trigger signal has a delay relative to the second trigger signal in the amount of a configurable number of cycles of the counter of the third control logic 112, 302, 304, 306, 812; a particle power source 106 comprising a second control logic 112, 302, 304, 306, 812 and configured to generate a particle power signal 118 in response to a third trigger signal; a radio frequency (RF) power source comprising a third control logic 112, 302, 304, 306, 812 and configured to generate an RF power signal 120 in response to the fourth trigger signal; a particle source 102 configured to generate a particle beam 114 in response to the particle power signal 118; An RF source 108, 808 configured to generate an RF signal in response to the RF power signal 120; and an accelerating structure 104 configured to accelerate the particle beam 114 in response to the RF signal.

Some embodiments provide a system comprising: first control logic 112, 302, 304, 306, 812, configured to receive a first trigger signal and generate a second trigger signal in response to the first trigger signal, wherein the second trigger signal has an adjustable second trigger delay. signal relative to the first initiating signal; second control logic 112, 302, 304, 306, 812, configured to receive a second trigger signal and generate a third trigger signal in response to the second trigger signal, wherein the third trigger signal has a configurable delay of the third trigger signal relative to the second trigger signal in an amount of configurable number of cycles; third control logic 112, 302, 304, 306, 812, configured to receive a second trigger signal and generate a fourth trigger signal in response to the second trigger signal, the fourth trigger signal having an adjustable delay of the fourth trigger signal relative to the second trigger signal; a particle power source 106 comprising a second control logic 112, 302, 304, 306, 812 and configured to generate a particle power signal 118 in response to a third trigger signal; a radio frequency (RF) power source comprising a third control logic 112, 302, 304, 306, 812 and configured to generate an RF power signal 120 in response to the fourth trigger signal.

In some embodiments, the system further comprises: a particle source 102 configured to generate a particle beam 114 in response to a particle power signal 118; An RF source 108, 808 configured to generate an RF signal in response to the RF power signal 120; and an accelerating structure 104 configured to accelerate the particle beam 114 in response to the RF signal.

In some embodiments, the configurable delay of the third trigger signal of the second control logic 112, 302, 304, 306, 812 is different from the configurable delay of the fourth trigger signal of the third control logic 112, 302, 304, 306, 812.

In some embodiments, the first control logic is configured to: receive a pulse message associated with the first trigger signal prior to the first trigger signal; transmitting a first control message to the second control logic 112, 302, 304, 306, 812 that indicates a configurable delay of the third trigger signal of the second control logic 112, 302, 304, 306, 812; and transmitting a second control message to the third control logic 112, 302, 304, 306, 812 that indicates a configurable delay of the fourth trigger signal of the third control logic 112, 302, 304, 306, 812.

In some embodiments, the third control logic 112, 302, 304, 306, 812 is configured to generate a control pulse in response to the fourth trigger signal; the RF power source 108, 808 is configured to generate an RF power signal 120 based on the control pulse; optionally, the third control logic 112, 302, 304, 306, 812 is configured to generate a control pulse based on a second adjustable delay of the fourth trigger signal of the third control logic 112, 302, 304, 306, 812.

In some embodiments, the system further comprises: a first high voltage power supply; and a second high voltage power supply separate from the first high voltage power supply; wherein: the particle power source 106 is configured to generate a particle power signal 118 in response to the third trigger signal using the first high voltage power source; wherein the radio frequency (RF) power source 108, 808 is configured to generate an RF power signal 120 in response to the fourth trigger signal using the second high voltage power supply.

In some embodiments, the configurable number of counter cycles of the second control logic 112, 302, 304, 306, 812 is different from the configurable number of counter cycles of the third control logic 112, 302, 304, 306, 812.

In some embodiments, the first control logic 112, 302, 304, 306, 812 is configured to execute an interrupt handler in response to the first trigger signal; moreover, the delay relative to the first initiating signal does not depend on when the execution time of the interrupt routine ends.

In some embodiments, the first control logic 112, 302, 304, 306, 812 is configured to: receive a pulse message associated with the first trigger signal prior to the first trigger signal; transmitting a first control message to the second control logic 112, 302, 304, 306, 812 that indicates a configurable number of counter cycles of the second control logic 112, 302, 304, 306, 812; and transmitting a second control message to the third control logic 112, 302, 304, 306, 812 that indicates a configurable number of counter cycles of the third control logic 112, 302, 304, 306, 812.

In some embodiments, the second control logic 112, 302, 304, 306, 812 is configured to generate a control pulse in response to a third trigger signal; and the particle power source 106 is configured to generate a particle power signal 118 based on the drive pulse.

In some embodiments, the second control logic 112, 302, 304, 306, 812 is configured to generate a control pulse based on a second configurable number of counter cycles of the second control logic 112, 302, 304, 306, 812.

In some embodiments, the third control logic 112, 302, 304, 306, 812 is configured to generate a control pulse in response to the fourth trigger signal; and the RF power source 110 is configured to generate a particle power signal 118 based on the drive pulse.

In some embodiments, third control logic 112, 302, 304, 306, 812 is configured to generate a control pulse based on a second configurable number of counter cycles of third control logic 112, 302, 304, 306, 812.

Some embodiments provide for a method including: receiving a first trigger signal; generating a second trigger signal in response to the first trigger signal, the second trigger signal having an adjustable delay of the second trigger signal relative to the first trigger signal; generating a third trigger signal in response to the second trigger signal, the third trigger signal having an adjustable delay of the third trigger signal relative to the second trigger signal; generating a fourth trigger signal in response to the second trigger signal, the fourth trigger signal having an adjustable delay of the fourth trigger signal relative to the second trigger signal; generating a particle power signal 118 in response to the third trigger signal; and generating a radio frequency (RF) power signal 122 in response to the fourth trigger signal.

In some embodiments, the method further includes generating particle beam 114 in response to particle power signal 118; generating an RF signal in response to the RF power signal 120; and accelerating the particle beam 114 in response to the RF signal.

In some embodiments, the configurable delay of the third trigger is different from the configurable delay of the fourth trigger.

In some embodiments, the method further includes receiving a pulse message associated with the first trigger signal prior to the first trigger signal; determining a configurable delay for a third trigger signal in response to the pulse message; and determining an adjustable delay of the fourth trigger signal in response to the pulse message.

In some embodiments, the method further includes generating a drive pulse, including generating a drive pulse based on a second configurable delay of the third trigger signal.

In some embodiments, the implementation of the method further includes generating a control pulse in response to the fourth initiating signal; wherein generating the RF power signal 120 includes generating the RF power signal 120 in response to the control pulse; and optionally generating the drive pulse includes generating a drive pulse based on a second adjustable delay of the fourth trigger signal.

Some embodiments provide for a method including: receiving a first trigger signal; generating a second trigger signal in response to the first trigger signal, the second trigger signal being delayed relative to the first trigger signal by a configurable number of first counter cycles; generating a third trigger signal in response to the second trigger signal, the third trigger signal being delayed relative to the second trigger signal by a configurable number of second counter cycles; generating a fourth trigger signal in response to the second trigger signal, the fourth trigger signal being delayed relative to the second trigger signal by a configurable number of third counter cycles; generating a particle power signal 118 in response to the third trigger signal; generating a radio frequency (RF) power signal 122 in response to the fourth trigger signal; generating a particle beam 114 in response to the particle power signal 118; generating an RF signal in response to the RF power signal 120; and accelerating the particle beam 114 in response to the RF signal.

In some embodiments, the configurable number of cycles of the second counter is different from the configurable number of cycles of the third counter.

In some embodiments, the method further includes: executing an interrupt handler in response to the first trigger signal; moreover, the delay relative to the first initiating signal does not depend on when the execution time of the interrupt routine ends.

In some embodiments, receiving a pulse message associated with the first trigger signal prior to the first trigger signal; determining a configurable number of cycles of the second counter in response to the pulse message; and determining a configurable number of cycles of the third counter in response to the pulse message.

In some embodiments, the implementation of the method further includes: generating a control pulse in response to the third initiating signal; wherein generating the particle power signal 118 includes generating the particle power signal 118 in response to the control pulse.

In some embodiments, generating a control pulse includes generating a control pulse based on a second configurable number of cycles of the second counter.

In some embodiments, generating a control pulse in response to a fourth trigger signal; wherein generating the RF power signal 120 includes generating the RF power signal 120 in response to the control pulse.

In some embodiments, generating a control pulse includes generating a control pulse based on a second configurable number of cycles of the third counter.

In some embodiments, generating a particle power signal 118 in response to a third trigger signal includes generating a particle power signal 118 using a first high voltage power supply 162b; and generating the RF power signal 120 in response to the fourth trigger signal includes generating the RF power signal 120 using a second high voltage power supply 162a separate from the first high voltage power supply.

Some embodiments provide a system comprising: means for receiving a first trigger signal; means for generating a second trigger signal in response to the first trigger signal, the second trigger signal being delayed relative to the first trigger signal by a configurable number of first counter cycles; means for generating a third trigger signal in response to the second trigger signal, the third trigger signal being delayed relative to the second trigger signal by a configurable number of second counter cycles; means for generating a fourth trigger signal in response to the second trigger signal, the fourth trigger signal being delayed relative to the second trigger signal by a configurable number of third counter cycles; means for generating a particle power signal in response to the third trigger signal; means for generating a radio frequency (RF) power signal in response to the fourth trigger signal; means for generating a particle beam in response to the particle power signal; means for generating an RF signal in response to the RF power signal; and means for accelerating the particle beam in response to the RF signal. Examples of means for receiving the first trigger signal include control logic 112 . Examples of means for generating a second trigger signal include control logic 112 . Examples of means for generating a third trigger signal include control logic 304 . Examples of means for generating a fourth trigger signal include control logic 306 . Examples of means for generating a particle power signal include a particle power source 106 . Examples of means for generating an RF power signal include an RF power source 110 . Examples of means for generating a particle beam include a particle source 102 . Examples of means for generating an RF signal include an RF source 108, 808. Examples of means for accelerating a particle beam include an accelerating structure 104.

In some embodiments, the system further comprises: means for executing an interrupt handler in response to the first trigger signal; moreover, the delay relative to the first initiating signal does not depend on when the execution time of the interrupt routine ends. Examples of means for executing an interrupt handler include control logic 112, 302, 304, 306.

Some embodiments provide means for receiving a first trigger signal; means for generating a second trigger signal in response to the first trigger signal, the second trigger signal having an adjustable delay of the second trigger signal relative to the first trigger signal; means for generating a third trigger signal in response to the second trigger signal, the third trigger signal having an adjustable delay of the third trigger signal relative to the second trigger signal; means for generating a fourth trigger signal in response to the second trigger signal, the fourth trigger signal having an adjustable delay of the fourth trigger signal relative to the second trigger signal; means for generating a particle power signal in response to the third trigger signal; means for generating a radio frequency (RF) power signal in response to the fourth trigger signal. Examples of means for receiving the first trigger signal include control logic 112 . Examples of means for generating a second trigger signal include control logic 112 . Examples of means for generating a third trigger signal include control logic 304 . Examples of means for generating a fourth trigger signal include control logic 306 .

In some embodiments, the system further comprises means for executing an interrupt handler in response to the first trigger, wherein the delay relative to the first trigger is independent of when the interrupt handler terminates; or optionally means for generating a particle beam in response to a particle power signal; or optionally means for generating an RF signal in response to the RF power signal; or optionally means for accelerating the particle beam in response to an RF signal. Examples of means for executing an interrupt handler include control logic 112, 302, 304, 306. Examples of means for generating a particle beam include a particle source 102 . Examples of means for generating an RF signal include an RF source 108, 808. Examples of means for accelerating a particle beam include an accelerating structure 104.

Some embodiments provide for a system comprising: an RF source 108, 808 configured to generate an RF signal; An RF frequency control circuit coupled to the RF source 108, 808 and configured to adjust the frequency of the RF signal; and control logic 112, 302, 304, 306, 812, configured to: receive a plurality of settings over time for the RF source 108, 808; adjusting the RF signal in response to settings; and adjusting the RF setpoint of the frequency control circuit in response to the settings.

In some embodiments, the system further comprises an accelerating structure 104 configured to accelerate the particle beam 114 in response to an RF signal.

In some embodiments, control logic 112, 302, 304, 306, 812 is configured to: maintain a settings history containing the most recent few settings from settings for RF source 108, 808; and adjusting the RF setpoint of the frequency control circuit 856 in response to the history.

In some embodiments, the control logic 112, 302, 304, 306, 812 is configured to initialize the setting history with a default setting for the RF source 108, 808.

In some embodiments, the control logic 112, 302, 304, 306, 812 is configured to: subdivide settings in history into energy level categories; selecting a category from the energy level categories with the most settings; and adjusting the RF set point of the frequency control circuit in response to the energy level associated with the selected category.

In some embodiments, the control logic 112, 302, 304, 306, 812 is configured to: combine the energy levels associated with history settings into a combined energy level; and adjusting an RF setpoint of the frequency control loop in response to the combined energy level.

In some embodiments, the control logic 112, 302, 304, 306, 812 is configured to: combine the energy levels associated with history settings into a combined energy level using weighting factors that increase with the energy level; and adjusting an RF setpoint of the frequency control loop in response to the combined energy level.

In some embodiments, the history spans a time less than or equal to 0.2 seconds.

In some embodiments, control logic 112, 302, 304, 306, 812 is configured to: receive an indication of the energy level for an incoming RF pulse; and adding an indication of the energy level to the history; or receiving an indication of the energy level for the incoming RF pulse, and adding the indication of the energy level to the history.

In some embodiments, control logic 112, 302, 304, 306, 812 is configured to: receive a pulse timing indication for an incoming RF pulse of RF signal 120; and changing the sampling timing of the one or more RF feedback signals in the frequency control circuit 856 for the RF source 108, 808 based on the pulse timing indication.

Some embodiments provide a method including: using an RF source 108, 808 to generate an RF signal 120 in response to a plurality of energy level settings over time; and adjusting the frequency of the RF source 108, 808 in response to the energy level settings.

In some embodiments, the method further includes accelerating the particle beam 114 in response to the RF signal 120.

In some embodiments, the method further includes: receiving a pulse timing indication for the incoming RF pulse; and changing the sampling timing of the RF feedback signals in the frequency control loop for the RF source 108, 808 based on the pulse timing indication.

In some embodiments, the method further includes: maintaining an energy level settings history containing the last few energy level settings so far; and adjusting the frequency of the RF source 108, 808 in response to the history.

In some embodiments, the method further includes initializing the energy level setting history with a default setting.

In some embodiments, the method further includes: categorizing history energy level settings according to energy level; selecting the category of energy level settings with the largest number of recent energy level settings at the moment; and adjusting the frequency of the RF source 108, 808 in response to the selected category.

In some embodiments, the method further includes: combining history energy level settings into a combined energy level; and adjusting the frequency of the RF source 108, 808 in response to the combined energy level.

In some embodiments, the method further includes: combining history energy level settings into a combined energy level using weighting factors that increase with energy level; and adjusting the frequency of the RF source 108, 808 in response to the combined energy level; or receiving an indication of the energy level for the incoming RF pulse, and adding the indication of the energy level to the history.

In some embodiments, maintaining a history of energy level settings includes maintaining a history spanning a time less than or equal to 0.2 seconds.

In some embodiments, the implementation of the method further includes: receiving an indication of the energy level for the incoming RF pulse; and adding an indication of the energy level to the history.

Some embodiments provide a system comprising: means for generating an RF signal in response to a plurality of energy level settings over time; and means for adjusting the frequency of the RF signal in response to the energy level settings. Examples of means for generating an RF signal include RF sources 108, 808, and the like. Examples of means for adjusting the frequency of the RF signal include an RF frequency control circuit 856 and a control logic 812.

In some embodiments, the system further comprises means for accelerating the particle beam in response to an RF signal. Examples of means for accelerating the particle beam include accelerating structure 104.

In some embodiments, the system further comprises: means for maintaining a settings history containing the most recent few of the settings for the RF signal; and means for adjusting a setpoint of means for adjusting the frequency of the RF source in response to the history. Examples of a means for adjusting the setting history include control logic 818. Examples of means for adjusting the setpoint include control logic 818.

As mentioned above, in one embodiment, the system comprises a particle power source configured to generate a particle power signal; and a radio frequency (RF) power source configured to generate an RF power signal; wherein the timing of the RF power signal is different from the timing of the particle power signal. The timing of the RF power signal, which is different from the timing of the particle power signal, can be provided by the following: a first control logic configured to receive a first trigger signal and generate a second trigger signal in response to the first trigger signal, wherein the second trigger signal has adjustable delay of the second trigger signal relative to the first trigger signal; a second control logic configured to receive a second trigger signal and generate a third trigger signal in response to the second trigger signal, the third trigger signal having an adjustable delay of the third trigger signal relative to the second trigger signal; and a third control logic configured to receive a second trigger signal and generate a fourth trigger signal in response to the second trigger signal, the fourth trigger signal having a configurable delay of the fourth trigger signal relative to the second trigger signal; the particle power source comprising a second control logic and configured to generate a particle power signal in response to the third trigger signal; and wherein the radio frequency (RF) power source comprises a third control logic and is configured to generate an RF power signal in response to the fourth trigger signal.

While structures, devices, methods, and systems have been described in accordance with particular embodiments, it will be apparent to one skilled in the art that many variations of particular embodiments are possible, and thus any variation should be considered to be within the spirit and scope, disclosed in this document. Accordingly, many modifications can be made by a person skilled in the art without departing from the spirit and scope of the appended claims.

The claims following this written description are expressly incorporated into this written description, with each claim being a separate embodiment. This disclosure includes all permutations of independent claims with dependent claims. Moreover, additional embodiments that may be derived from the independent and dependent claims are also expressly incorporated herein in writing. These additional embodiments are defined by replacing the dependency of a given dependent claim with the phrase "any of the claims beginning with [x] and ending with the claim immediately preceding that claim", where the bracketed term "[x]" is replaced by the number the most recently claimed independent claim. For example, for a first set of claims that starts with independent claim 1, claim 3 may depend on any of claims 1 and 2, with these separate dependencies giving two different embodiments; item 4 may depend on any of items 1, 2 or 3, with these separate dependencies giving three different implementation options; item 5 may depend on any of items 1, 2, 3, or 4, with these separate dependencies giving four different implementation options; and so on.

6. Варианты осуществления изобретения, в которых испрашивается исключительное свойство или привилегия, определяются следующим образом.Reference in the claims to the term "first" in relation to a feature or element does not necessarily imply the presence of a second or additional such feature or element. Elements specifically listed in the "means plus function" format, if any, are intended to be construed to cover the respective design, material, or operation described herein and their equivalents pursuant to 35 USC § 112

6. Embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

Claims (57)

1. A frequency control system for a tunable linear accelerator, comprising: An RF source configured to generate an RF signal; RF frequency control circuit connected to the RF source and configured to adjust the frequency of the RF signal; an accelerating structure configured to accelerate the particle beam in response to the RF signal; and control logic configured to: receiving a plurality of settings over time for the RF source; maintaining a settings history including the latest few settings from said set of settings for the RF source; adjusting the current RF signal in response to multiple settings; and adjusting the current RF setpoint of the frequency control circuit in response to a combination of at least two of the most recent settings at different times in history, wherein said set of settings are energy level settings for the RF source. 2. The system of claim 1, wherein the control logic is configured to initialize the most recent settings in history to the current moment with the RF source default setting for each of the most recent settings. 3. The system according to claim 1 or 2, in which the control logic is configured to: subdividing settings in history into energy level categories; selecting a category from the energy level categories with the most settings; and adjusting the current RF setpoint of the frequency control loop in response to the energy level associated with the selected category. 4. The system according to any one of paragraphs. 1-3, in which the control logic is configured to: combining energy levels associated with settings in history into a combined energy level; and adjusting the current RF setpoint of the frequency control loop in response to the combined energy level. 5. The system according to any one of paragraphs. 1-4, in which the control logic is configured to: combining the energy levels associated with settings in history into a combined energy level using weighting factors that increase with the energy level, and adjusting the RF setpoint of the frequency control loop in response to the combined energy level. 6. The system according to any one of paragraphs. 1-5, in which the history spans a time less than or equal to 0.2 seconds. 7. The system according to any one of paragraphs. 1-6, in which the control logic is configured to: receiving an indication of an energy level for the incoming RF pulse; and adding an indication of the energy level to the history. 8. The system according to any one of paragraphs. 1-7, in which the control logic is configured to: receiving a pulse timing indication for the incoming RF pulse of the RF signal; and changing the sampling timing of the one or more RF feedback signals in the RF frequency control loop based on the pulse timing indication. 9. A method for operating a tunable linear accelerator, including: using an RF source to generate an RF signal in response to a plurality of energy level settings for the RF source over time; maintaining a history of a plurality of energy level settings including the most recent few of said plurality of energy level settings for the RF source; accelerating the particle beam in response to the RF signal; and adjusting the current setpoint of the RF source in response to a combination of at least two of the most recent settings at different times in history. 10. The method of claim 9, further comprising: receiving a pulse timing indication for the incoming RF pulse; and changing the sampling timing of the RF feedback signals in the frequency control loop for the RF source based on the pulse timing indication. 11. The method according to claim 9 or 10, further comprising initializing the latest settings in the history of the plurality of energy level settings with a default setting for each of the latest settings. 12. The method according to any one of paragraphs. 9-11 further including dividing the history energy level settings into categories according to the energy level; selecting the category of energy level settings with the largest number of recent energy level settings at the moment; and adjusting the current RF source setpoint in response to the selected category. 13. The method according to any one of paragraphs. 9-12, further comprising: combining a plurality of history energy level settings into a combined energy level; and adjusting the current RF source setpoint in response to the combined energy level. 14. The method according to any one of paragraphs. 9-13, further comprising: combining multiple energy level settings in history into a combined energy level using weighting factors that increase with energy level, and adjusting the current RF source setpoint in response to the combined energy level. 15. The method according to any one of paragraphs. 9-14, wherein maintaining the setting history includes maintaining a history spanning a time less than or equal to 0.2 seconds. 16. The method according to any one of paragraphs. 9-15, further comprising: receiving an indication of an energy level for the incoming RF pulse; and adding an indication of the energy level to the history. 17. Frequency control system for a tunable linear accelerator, comprising: means for generating an RF signal in response to a plurality of energy level settings for means for generating an RF signal over time; means for maintaining a history of a plurality of energy level settings including the most recent few of said plurality of energy level settings for the RF source; means for accelerating the particle beam in response to the RF signal; means for adjusting the frequency of the RF signal; and means for adjusting a current setpoint of means for adjusting the frequency of the RF signal in response to a combination of at least two of the most recent settings at different times in history. 18. The system of claim 17 further comprising means for accelerating the particle beam in response to an RF signal.

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