JP2006228579A - Accelerator system and its operation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accelerator system capable of making loads to an electric power system smaller, and to provide its operating method. <P>SOLUTION: The system is provided with a first accelerator 1 for accelerating an ion beam until it becomes to have a set energy, a beam transport system 2 to transport the ion beam emitted from the accelerator 1, electromagnet power supplies 3, 4 to carry out excitation of an electromagnet to be provided for the accelerator 1 and the beam transport system 2, and a control device 5 to control the electromagnet power supplies 3, 4 so as to carry out initialization of the electromagnet, belonging to the accelerator 1 after carrying out the initialization of the electromagnet, belonging to the beam transport system 2 in the initialization operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an accelerator system including an accelerator and a beam transport system, and more particularly to an accelerator system in which beam energy is changed.

  In recent years, particle accelerator systems have been used not only for research on high energy physics so far, but also for medical use such as generation of radioisotopes and particle beam therapy for cancer, industrial use such as material irradiation, agricultural use such as seed irradiation, etc. It is used for various purposes, and a single accelerator may be used for multiple purposes.

  In general, an accelerator system accelerates a charged particle beam generated and incident from a charged particle source to a predetermined energy, for example, an accelerator such as a synchrotron, and transports the charged particle beam emitted from the accelerator to an irradiation device. And a beam transport system. These accelerators and beam transport systems include many electromagnets such as a deflection electromagnet, a quadrupole electromagnet, and a steering electromagnet.

  In the operation of such an accelerator system, normally, on the accelerator side, for example, a pattern operation is performed in which the electromagnet is excited by the excitation pattern of the electromagnet set as one operation cycle of “incidence → acceleration → extraction → demagnetization”, In the beam transport system, a set value operation for exciting the electromagnet with the set excitation current is performed. Thus, for example, when performing extraction with a constant beam energy, the accelerator performs a pattern operation in which the excitation current at the time of extraction is constant, and the beam transport system performs a set value operation with a constant set excitation current corresponding to the energy. Is done.

  Among such accelerator systems, for example, in an accelerator system used for particle beam therapy, the distance (range) of charged particles in the body in the depth direction is determined by the beam energy. The beam energy corresponding to the height is set, and treatment irradiation is performed with the energy. Therefore, when the patient (affected part) to be treated changes, the beam energy needs to be changed to an appropriate value set for each patient (affected part) and emitted. In particular, in an irradiation method called scanning in which a thin beam is scanned into the affected area, the affected area is divided into a plurality of layers in the depth direction, and the affected area is irradiated by scanning the beam for each layer. It is necessary to change the beam energy, and it is necessary to frequently change the beam energy even in the same patient (affected part).

When the beam energy is changed in this way in the operation of the accelerator system, it is necessary to change to a pattern operation in which the excitation current at the time of extraction is different in the accelerator, and to a set value operation in which the set excitation current is different in the beam transport system. When the excitation current of the electromagnet is changed in this way, an initialization operation is necessary to erase the operation history of the electromagnet, that is, the hysteresis (magnetic history) of the electromagnet. Conventionally, as an operation method of the initialization operation of the accelerator system, there is one in which the accelerator and the electromagnet group of the beam transport system are simultaneously excited with a maximum current (see, for example, Patent Document 1).
Japanese Patent No. 2857598 (FIG. 7)

  In the above prior art, the accelerator system is initialized by exciting all the electromagnets of the accelerator and the beam transport system simultaneously with the maximum current. Therefore, since it is necessary to simultaneously maximize the excitation current value of each electromagnet for a large number of electromagnets during the initialization operation, the load on the power system has become very large.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide an accelerator system that can reduce a load on an electric power system and an operation method thereof.

  The feature of the present invention that achieves the above-described object is that an accelerator that accelerates a charged particle beam to a set energy, a beam transport system that transports the charged particle beam emitted from the accelerator, the accelerator, and the accelerator An electromagnet power source for exciting an electromagnet provided in a beam transport system, and the electromagnet power source so as to initialize the electromagnet belonging to the accelerator after the electromagnet belonging to the beam transport system in the initialization operation. And a control device for controlling the operation. As a result, the initialization operation of the accelerator system can be performed by shifting the timing of the initialization of the electromagnet belonging to the accelerator and the initialization of the electromagnet belonging to the beam transport system, thereby reducing the power required for the initialization operation. The load on the power system can be reduced. Furthermore, by shifting the timing in this manner, the electromagnet belonging to the accelerator can be initialized after the initialization of the electromagnet belonging to the beam transport system is completed and the operation is performed with a substantially constant excitation current (normal operation). It becomes possible. In this way, the initialization on the accelerator side can be performed after the power on the beam transport system side is leveled, so disturbances to the power system can be reduced, and this can also reduce the load on the power system. .

  ADVANTAGE OF THE INVENTION According to this invention, the load with respect to an electric power grid | system can be made small.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiment is an example in which the present invention is applied to a particle beam therapy system for treating cancer or the like.

(Embodiment 1)
FIG. 1 is an overall configuration diagram of a particle beam therapy system according to a preferred embodiment of the present invention.

  In FIG. 1, the particle beam therapy system of this embodiment includes an accelerator 1 that accelerates an ion beam (charged particle beam) to a predetermined energy, and a rotation (not shown) of the ion beam accelerated and emitted by the accelerator 1. The beam transport system 2 transported to the gantry irradiation device, the accelerator electromagnet power source (electromagnet power source) 3 for exciting the electromagnet groups provided in the accelerator 1 and the electromagnet group provided in the beam transport system 2 are respectively excited. And a control device 5 that controls the transport system electromagnet power source (electromagnet power source) 4.

  The accelerator 1 includes an incident device 6 and a main accelerator 7. In the present embodiment, for example, a synchrotron is used as the main accelerator 7 (hereinafter referred to as synchrotron 7). The incident device 6 includes an ion source 8, an incident transport system 9 including an incident septum electromagnet SM1, and the like. Since this incident device 6 always injects an ion beam of substantially constant energy into the synchrotron 7, the electromagnet power source provided in the incident transport system 9 is energized with a substantially constant excitation current.

  The synchrotron 7 includes a plurality of (six in this embodiment) deflection electromagnets B, a plurality (12 in this embodiment) four-pole electromagnets Q, and a plurality (three in this embodiment) of six. It is composed of polar electromagnets SX1 to SX3 and a plurality (seven in this embodiment) of steering electromagnets St1 to st7. In addition to these, an octopole electromagnet may be provided. The number of each electromagnet may vary depending on the design and is not limited to this. Furthermore, there are actually special electromagnets for entering and exiting, but since they are not directly related to the present invention, illustration and explanation are omitted.

  The six deflection electromagnets B are serially excited by one electromagnet power source B-ps, and the twelve quadrupole electromagnets Q including a plurality of converging 4-poles and diverging 4-poles are serially connected by one electromagnet power source Q-ps. Excited. The three hexapole magnets SX1 to SX3 are individually excited by the electromagnetic power sources SX1-ps to SX3-ps, and the seven steering magnets St1 to st7 are individually excited by the electromagnetic power sources St1-ps to St7-ps. The These electromagnet power supplies B-ps, Q-ps, SX1-ps to SX3-ps, and St1-ps to St7-ps are provided in the accelerator electromagnet power supply 3 described above.

  The electromagnet group provided in the beam transport system 4 is composed of a plurality of deflection electromagnets HB1 to HBn, a plurality of quadrupole electromagnets HQ1 to HQn, a plurality of steering electromagnets HSt1 to HStn, etc., and the total number is around 100 units. (It is not limited to this number). Each electromagnet of these beam transport systems 2 is individually excited by one electromagnet power source. That is, the deflection electromagnets HB1 to HBn are excited by the electromagnet power supplies HB1-ps to HBn-ps, respectively, and the quadrupole electromagnets HQ1 to HQn are respectively excited by the electromagnet power supplies HQ1-ps to HQn-ps, and the steering electromagnets HSt1 to HStn are electromagnets Excited by power supplies HSt1-ps to HStn-ps. These electromagnet power supplies HB1-ps to HBn-ps, HQ1-ps to HQn-ps, and HSt1-ps to HStn-ps are provided in the transport system electromagnet power supply 4.

  FIG. 2 is a diagram schematically showing the internal configuration of the control device 5. In FIG. 2, the deflecting electromagnet B, the quadrupole electromagnet Q, the hexapole electromagnets SX1 to SX3, the steering electromagnets St1 to St7, and the exit septum SM2 of the synchrotron 7 are the electromagnets on the accelerator side. The electromagnet provided in the incident device 6 is not included in the accelerator-side electromagnet because the required power is small and negligible compared to the synchrotron 7 side. These accelerator-side electromagnets are pattern electromagnets that are excited with a substantially trapezoidal current pattern, and are excited by the accelerator electromagnet power source 3 based on the control of the control device 5 as described above to perform pattern operation. On the other hand, the modified electromagnets HB1 to HBn, the quadrupole electromagnets HQ1 to HQn and the steering electromagnets HSt1 to HStn, which are electromagnets of the beam transport system 2, are used as the electromagnets on the transport system side. These electromagnets on the transport system side are excited with a current set value corresponding to the beam energy transported by the transport system electromagnet power source 4 based on the control of the control device 5 as described above, and perform set value operation.

  As shown in FIG. 2, the control device 5 includes a storage device 15, an output device 16 that outputs a current command value stored in the storage device 15 to the accelerator electromagnet power supply 3, and a current stored in the storage device 15. An output device 17 for outputting the command value to the transport electromagnet power source 4 is incorporated.

  In the storage device 15, current command values necessary for the operation of each electromagnet are stored in advance (or may be input as appropriate). FIG. 3 is a diagram schematically illustrating the storage contents of the storage device 15.

  As shown in FIG. 3, in the storage device 15, the current command value to be output to the electromagnet power sources 3 and 4 is divided into an accelerator system command value 18 for the accelerator system and a transport system command value 19 for the transport system. Is remembered. The accelerator system command value 18 includes an initialization pattern (INIT (B), INIT (Q),...) Necessary for initialization operation, an operation pattern (P1 (B), P1 (Q),. ) And the like, and the transport system command value 19 similarly includes a current command value for initialization operation (INIT (HB1), INIT (HQ1),...), A current command value for normal operation (C1 (HB1 ), C1 (HQ1),... Further, these current command values 18 and 19 have the number of repetitions for outputting to the electromagnet power source for each command value. The output device 16 and the output device 17 are configured to output the designated pattern for the number of repetitions.

  As shown in FIG. 3, the current command value necessary for the initialization operation is given as a substantially trapezoidal pattern on the accelerator side and a substantially rectangular wave pattern on the transport system side. The range of the magnitude of the current command value is It is between the minimum value 0% and the maximum value 100%. In this embodiment, the number of repetitions is set to 3 for both the accelerator side and the transport system side. Therefore, during the initialization operation, the initialization pattern is repeated three times (three periods) in the accelerator 1, and the beam transport system 2 is also initialized. The pattern (rectangular wave) is repeated 3 times (3 periods). Here, the number of times the initialization operation pattern is repeated is set to three, but is not limited thereto, and may be one, two, or four or more times.

  Returning to FIG. 2, the control device 5 further includes a sequencer (delay device) 20. The function of the sequencer 20 will be described below.

  When the initialization operation is started, an initialization start command 21 is first output from the sequencer 20 to the output device 17. The output device 17 receives the initialization start command 21 and repeats the current command value (INIT (HB1), INIT (HQ1),...) For the transport system command value 19 for the transport system command value 19 repeatedly. After outputting the minute (in this embodiment, three times), the current command value for normal operation (C1 (HB1), C1 (HQ1),...) Is outputted. When the initialization operation of each electromagnet of the beam transport system 2 is completed, an initialization completion signal 22 of each electromagnet power source of the transport system electromagnet power source 4 is output to the sequencer 20. When all initialization completion signals 22 of the transport system electromagnet power supply 4 are input to the sequencer 20, an accelerator system initialization start command 23 is output from the logic AND1 of the sequencer 20 to the output device 16 via the logic AND2. The Upon receiving the initialization start command 23, the output device 16 outputs the initialization pattern (INIT (B), INIT (Q,...) Of the accelerator side command value 18 to the accelerator electromagnet power source 3 for the number of times of repetition, and performs normal operation. Pattern (P1 (B), P1 (Q), ...) When the initialization operation of each electromagnet of the accelerator 1 is completed, the initialization completion signal 24 of each electromagnet power supply of the accelerator electromagnet power supply 3 is sent to the sequencer 20 When all the initialization completion signals 24 of the accelerator electromagnet power supply 3 are input to the sequencer 20, an accelerator system whole initialization completion signal 25 is issued from the logic AND3, and the process proceeds to treatment start.

  FIG. 4 shows the time change of the current command value output from the control device 5 to the transport system electromagnet power supply 4 and the accelerator electromagnet power supply 3 by the function of the sequencer 20 as described above. In FIG. 4, only current command values for two electromagnets are shown for the transport electromagnet power supply 4 and the accelerator electromagnet power supply 3 for the purpose of preventing complexity.

  As shown in FIG. 4, when the initialization operation is started, the current command values (INIT (HB1), INIT (HQ1),...) For the initialization operation are first output to the transport electromagnet power source 4. When initialization of all the electromagnets in the beam transport system 2 is completed, the current command values for normal operation (C1 (HB1), C1 (HQ1),...) Are output to the transport system electromagnet power source 4 and the accelerator. When the initialization pattern for three times (INIT (B), INIT (Q,...) Is output to the electromagnet power source 3 and initialization of all the electromagnets in the accelerator 1 is completed, the normal operation for the accelerator electromagnet power source 3 is performed. The pattern (P1 (B), P1 (Q), ...) is output.

The operation of the particle beam therapy system according to this embodiment having the above-described configuration will be described.
First, before accelerating the ion beam, initialization of the accelerator system, that is, initialization of the electromagnets provided in the accelerator 1 and the beam transport system 2 is performed for the purpose of eliminating the hysteresis (magnetic history) of the electromagnet. That is, as described above, the initialization start command 21 is output from the sequencer 20 to the output device 17, and the current command values (INIT (HB1), INIT (HQ1),. It is output three times to the transport system electromagnet power source 4, and first the electromagnet of the beam transport system 2 is initialized. When the initialization is completed, current command values (C1 (HB1), C1 (HQ1),...) For normal operation are continuously output from the output device 17 to the transport system electromagnet power source 4 and the beam of the beam transport system 2 A set value operation is performed with a substantially constant set excitation current corresponding to the energy. Further, an accelerator system initialization start command 23 is output from the sequencer 20 to the output device 16, and an initialization pattern (INIT (B), INIT (Q),...) Of the accelerator system command value 18 is sent to the accelerator electromagnet power source 3. It is output three times, and the electromagnet of the accelerator 1 is initialized. When the initialization of the accelerator 1 electromagnet is completed, the normal operation pattern (P1 (B), P1 (Q),...) Is output to the accelerator electromagnet power supply 3 and the accelerator 1 “injection → acceleration → extraction → decrease” Pattern operation is performed with “magnetic” as one operation cycle.

  When the initialization operation is completed as described above, normal operation of the accelerator system is performed. In this normal operation, ions (for example, positive ions (or carbon ions)) generated in the ion source 8 are incident on the synchrotron 7 through the incident transport system 9. At this time, the excitation current led to various electromagnets such as the deflection electromagnet B and the quadrupole electromagnet Q of the synchrotron 7 is made substantially constant to the incident current set value by the accelerator electromagnet power source 3 based on the control of the control device 5 described above. Is retained. In the synchrotron 7, the ion beam is accelerated by being given energy by application of high-frequency power from an acceleration high-frequency power source (not shown). At this time, the current values of the various electromagnets of the synchrotron 7 are controlled by the accelerator electromagnet power source 3 based on the control of the control device 5 so as to increase as the beam energy increases. The ion beam circulating in the synchrotron 7 is accelerated to a set energy (for example, 100 to 200 MeV) and then emitted from the synchrotron 7. That is, a high frequency from an extraction high-frequency power source (not shown) is applied to the circulating ion beam, and the ion beam circulating within the stability limit moves outside the stability limit and passes through the extraction deflector (not shown). Are emitted. Note that when the ion beam is emitted, the current guided to the various electromagnets of the synchrotron 7 is held substantially constant at the current setting value for extraction, and the stability limit is also kept substantially constant.

  The ion beam emitted from the synchrotron 7 is transported by the beam transport system 2 to an irradiation device provided in a rotating gantry (not shown) of a treatment room selected from the three treatment rooms. At this time, the current guided to the electromagnet corresponding to the selected treatment room (course) among the various electromagnets of the beam transport system 2 is synchronized with the synchrotron 7 by the transport system electromagnet power source 4 based on the control of the control device 5 described above. Is maintained at a current setting value corresponding to the energy of the ion beam emitted from the. Then, the ion beam transported to the irradiation device is irradiated from the irradiation device to the affected part of the patient 11 on the treatment table 10.

  When the treatment irradiation is performed as described above and the irradiation is completed and the patient 11 (or the affected part to be treated) is changed, the beam energy is changed. Initialization operation is performed. At this time, the current command value for normal operation (C1 (HB1), C1 (HQ1),...) Stored in the storage device 15 and the normal operation pattern (P1 (B), P1 ( Q), ...) are the current command values (C1 (HB1), C1 (HQ1), ...) and operation patterns (P1 (B), P1 (Q), ...) corresponding to the new patient 11 (or affected part). After the initialization operation is completed, normal operation of the accelerator system described above is performed based on the new current command value and operation pattern.

  According to the first embodiment described above, the initialization operation of the accelerator system can be performed by shifting the timing of the initialization of the electromagnet of the beam transport system 2 and the initialization of the electromagnet of the accelerator 1 as shown in FIG. Therefore, the power required for the initialization operation can be reduced, and the load on the power system can be reduced. Further, by shifting the timing in this way, the electromagnet of the synchrotron 7 can be initialized after the initialization of the electromagnet of the beam transport system 2 is completed and the normal operation is performed with a substantially constant set excitation current. . In this way, initialization on the accelerator side can be performed after the power on the transport system side is leveled, so disturbances to the power system can be reduced, and this also reduces the load on the power system. be able to.

(Embodiment 2)
FIG. 5 is a diagram schematically showing the internal configuration of the control device 5A of the present embodiment, and corresponds to FIG. 2 of the first embodiment. Components similar to those in FIG. 2 are denoted by the same reference numerals and description thereof is omitted.

  In this embodiment, the electromagnet group of the beam transport system 2 is divided into a plurality of groups. In this example, the number of groups is 2. At this time, the grouping is performed so that the sum of the maximum values of the initialization currents of the electromagnets belonging to each group is equal in each group. As shown in FIG. 5, the first group of electromagnets (electromagnet power source) 4A excites the first group of electromagnets, and the second group of transport electromagnet power sources (electromagnet power source) 4B excites the second group. The electromagnet is excited.

  FIG. 6 is a diagram schematically illustrating the storage contents of the storage device 15 in the present embodiment, and corresponds to FIG. 3 of the first embodiment. Portions similar to those in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 6, the transport system command value 19A output to the first transport system electromagnet power source 4A and the transport system command value 19B output to the second transport system electromagnet power source 4B are current commands for normal operation. Although the values are the same, the rectangular wave-shaped current command value for initialization operation has a phase shifted by 180 °. That is, the command value (transport system command value 19A) side related to the first group has a waveform starting from the minimum current, and the command value (transport system command value 19B) side related to the second group starts from the maximum current. The waveform is At this time, the transport system command value 19A and the transport system command value 19B have the same time width between the maximum value and the minimum value of the rectangular wave. This is reasonable because the current settling time is equal to the current command maximum value and the minimum value. Further, the time width (= minimum value time) of the maximum value of the rectangular wave is the same for all electromagnets. The accelerator side command value 18 is the same as that in the first embodiment.

Returning to FIG. 5, the function of the sequencer 20A built in the control device 5A will be described.
When the initialization operation is started, an initialization start command 21 is output from the sequencer 20A to the output devices 16, 17A, and 17B (also output to a delay circuit 27 described later). Thus, the output device 16 outputs the initialization pattern (INIT (B), INIT (Q),...) Of the accelerator side command value 18 to the accelerator electromagnet power source 3 three times, and then outputs the normal operation pattern (P1 (B ), P1 (Q), ...). Further, the output device 17A outputs the current command value (INIT (HB1), INIT (HQ1),. Outputs the current command value for normal operation (C1 (HB1), C1 (HQ1), ...). Further, the output device 17B outputs the current command value (INIT (HB2), INIT (HQ2),...) For the initialization operation of the transport system command value 19B to the second transport system electromagnet power source 4B three times, Outputs the current command value for normal operation (C1 (HB2), C1 (HQ2), ...).

  When the initialization of the electromagnets of the accelerator 1 and the beam transport system 2 is completed as described above, the entire accelerator system initialization completion signal 25 is issued from the delay circuit 27, and the process proceeds to the start of treatment. The delay time by the delay circuit 27 is set in advance to a time required for initialization of each electromagnet of the accelerator 1 and the beam transport system 2. In this embodiment, the treatment start timing is set by the delay circuit 27, but the treatment is performed using the initialization operation completion signal from each of the electromagnet power supplies 3, 4A, 4B as in the first embodiment. You may make it transfer to a start.

  FIG. 7 shows the time change of the current command value output from the control device 5A to the accelerator electromagnet power source 3 and the transport system electromagnet power sources 4A and 4B by the function of the sequencer 20A as described above.

  According to the embodiment 2 described above, the initialization operation of the electromagnets divided into the two groups of the beam transport system 2 is performed by the current command value waveform whose phase is shifted by 180 °, so that the initialization operation on the transport system side is performed. The necessary current is canceled out, and the current value is half that of the case where the entire transportation system is collectively initialized with the same current command value. Therefore, the load on the power system can be reduced. In addition, since the increase and decrease in current on the transport system side are offset, the disturbance applied to the power system can be reduced, and the load on the power system can also be reduced. Furthermore, in this embodiment, since the electric power required for the initialization operation on the transportation system side can be leveled, the initialization operation on the transportation system side and the accelerator side is performed simultaneously in parallel. As a result, the time required for the initialization operation can be shortened as compared with the first embodiment in which the initialization operations on the transport system side and the accelerator side are shifted.

(Embodiment 3)
FIG. 8 is a diagram schematically showing the internal configuration of the control device 5B of the present embodiment, and corresponds to FIG. 5 of the second embodiment. Portions similar to those in FIG. 5 are denoted by the same reference numerals, and description thereof is omitted.

  Also in this embodiment, the electromagnet group of the beam transport system 2 is divided into two groups as in the second embodiment. The dividing method is the same as that in the second embodiment. The difference from the second embodiment is that the same current command value is output at different timings to the first and second electromagnet power supplies 4A and 4B corresponding to each group. That is, the accelerator system command value 18 and the transport system command value 19 are stored in the storage device 15 of the present embodiment, and the configuration thereof is the same as that of the first embodiment. Then, the transport system command value 19 is output to the electromagnet power supplies 4A and 4B corresponding to each group by shifting the timing by the sequencer 20B. Hereinafter, the function of the sequencer 20B will be described.

  When the initialization operation is started, an initialization start command 21 is output from the sequencer 20B to the output devices 16 and 17A (also output to a delay circuit 28 and a delay circuit 29 described later). Thus, the output device 16 outputs the initialization pattern (INIT (B), INIT (Q),...) Of the accelerator side command value 18 to the accelerator electromagnet power source 3 three times, and then outputs the normal operation pattern (P1 (B ), P1 (Q), ...). Further, the output device 17A outputs the current command value (INIT (HB1), INIT (HQ1),...) For the initialization operation of the transport system command value 19 to the first electromagnet power source 4A three times, and then performs normal operation. Current command values (C1 (HB1), C1 (HQ1), ...) are output.

Next, an initialization start command 21 is output from the delay circuit (delay device) 28 to the output device 17B with a predetermined time delay. The delay time by the delay circuit 28 is set to the time width of the maximum value (minimum value) of the rectangular wave of the transport system command value 19. As a result, the output device 17B outputs the current command value (INIT (HB1), INIT (HQ1),...) For the initialization operation of the transport system command value 19 to the second transport system electromagnet power source 4B three times. ,
Outputs the current command value for normal operation (C1 (HB1), C1 (HQ1), ...).

  When all the initialization operations of the electromagnets of the accelerator 1 and the beam transport system 2 are completed as described above, the entire accelerator system initialization completion signal 25 is issued from the delay circuit 29, and the treatment is started. The delay time of the delay circuit 29 is set in advance to a time required for initialization of the electromagnets of the accelerator 1 and the beam transport system 2. In the present embodiment, the treatment start timing is set by the delay circuit 29, but the treatment is performed using the initialization operation completion signal from each of the electromagnet power sources 3, 4A, 4B as in the first embodiment. You may make it transfer to a start.

  FIG. 9 shows the time change of the current command value output from the control device 5B to the accelerator electromagnet power supply 3 and the transport system electromagnet power supplies 4A and 4B by the function of the sequencer 20B as described above.

  According to the present embodiment described above, the same effect as in the second embodiment can be obtained.

  In Embodiments 2 and 3 described above, the electromagnet group of the beam transport system 2 is divided into two groups, but the number of groups is not limited to this and may be increased. For example, if it is classified into 3 groups, it may be grouped so that the sum of the maximum values of the initialization currents of the electromagnets belonging to the first group and the second and third groups is equal, for example, 4 groups. Then, it is sufficient that the sum of the maximum values of the initialization currents of the electromagnets belonging to the first and second groups and the third and fourth groups is equal.

(Embodiment 4)
FIG. 10 is a diagram schematically showing the internal configuration of the control device 5C of the present embodiment, and corresponds to FIG. 2 and the like of the first embodiment described above. The same parts as those in FIG.

  Since the configurations of the initialization current command values 18 and 19 and the configurations of the output devices 16 and 17 stored in the storage device 15 of the present embodiment are the same as those of the first embodiment, description thereof will be omitted.

  In this embodiment, the current command value for the transport system electromagnet power supply 4 is individually given for each electromagnet power supply corresponding to each electromagnet. That is, the sequencer 20C outputs the initialization start command 21 to the output device 17 individually for each electromagnet power source. Specifically, as shown in FIG. 10, the initialization start command 21 is input to the delay circuit (delay device) 30 in the sequencer 20C, and the delay circuits 30-b2 to 30- corresponding to the respective electromagnet power supplies in the circuit. Delayed sequentially by st2 to. As a result, the initialization start command 21 is sequentially output to the output device 17, and the output device 17 that has received them first outputs the transport system command value 19 to the transport system electromagnet power source HB1-ps, and sequentially HB2-ps. Output to ~ Hst2-ps ~. As a result, the initialization operation of each electromagnet of the corresponding beam transport system 2 is sequentially performed by each electromagnet power supply of the transport system electromagnet power supply 4.

  Each delay width Δt (seconds) by the delay circuit 30 can be set individually, but in this example, it is a uniform value. For example, when the time of one electromagnet initialization time (0% -100%) is 10 seconds and the number of transport electromagnet power supplies 4 is 100, the magnitude of Δt is one initialization time. From the standpoint of leveling the initialization currents of all the transport system electromagnet power sources 4, it is preferable to set 10 (seconds) / 100 (units) = 0.1 seconds (see FIG. 11 described later). ).

  When all the initialization operations of the electromagnets of the accelerator 1 and the beam transport system 2 are completed, the accelerator system whole initialization completion signal 25 is issued from the delay circuit 31, and the point of shifting to the start of treatment is the second embodiment described above. , 3. However, similarly to the above-described first embodiment, the start of treatment may be started using the initialization operation completion signal from each of the electromagnet power supplies 3 and 4.

  FIG. 11 shows the time change of the current command value output from the control device 5C to the accelerator electromagnet power source 3 and the transport system electromagnet power source 4 by the function of the sequencer 20C as described above.

  According to the present embodiment described above, the electric power required for initializing the electromagnet of the beam transport system 2 is larger than that of the above-described second and third embodiments, but the current change of each electromagnet of the beam transport system 2 Since the timing can be positively shifted and leveled, disturbances to the power system can be suppressed, thereby reducing the load on the power system. In particular, when a command value such as an initialization start command is realized by communication typified by serial transmission, a delay in command due to transmission is inevitable in principle, but this delay is used as a delay by the delay circuit 30 of the present embodiment. If this is taken into consideration, a rational control system can be constructed.

(Embodiment 5)
FIG. 12 is a diagram schematically showing an internal configuration of the control device 5D of the present embodiment, and corresponds to FIG. 2 and the like of the first embodiment. The same parts as those in FIG.

  In this embodiment, the electromagnet group of the accelerator 1 is divided into a plurality of groups. In this example, it is divided into two groups of a deflection electromagnet B and other electromagnet groups. This is because the excitation current of the deflection electromagnet B is dominant in the synchrotron 7 and the sum of the maximum initialization current of the deflection electromagnet B and the maximum initialization current of the other electromagnets is almost equal. is there. Note that other combinations may be used. As shown in FIG. 12, the first accelerator electromagnet power source (electromagnet power source) 3A excites the first group of electromagnets (ie, deflection electromagnet B), and the second accelerator electromagnet power source (electromagnet power source) 3B Two groups of electromagnets (that is, electromagnets other than the deflection electromagnet B) are excited.

  The storage device 15 of the present embodiment stores an accelerator system command value 18 and a transport system command value 19, and the configuration thereof is the same as that of the first embodiment. The accelerator system command value 18 is output to the electromagnet power supplies 3A and 3B corresponding to the above groups by shifting the timing by the sequencer 20D. The function of this sequencer 20D will be described.

  When the initialization operation is started, an initialization start command 21 is first output from the sequencer 20D to the output device 16A (also output to a delay circuit 32 and a delay circuit 34 described later). As a result, the output device 16A outputs the initialization pattern (INIT (B), INIT (Q),...) Of the accelerator side command value 18 three times to the accelerator electromagnet power source 3A, and then outputs the normal operation pattern (P1 (B ), P1 (Q), ...). Next, an initialization start command 21 is output from the delay circuit (delay device) 32 to the output device 16B with a predetermined time delay. The delay time of the delay circuit 32 can be arbitrarily set. For example, the flat portion (flat top or flat) of the initialization current command value (initialization pattern) having a substantially trapezoidal shape of the accelerator electromagnet power supply 3A related to the first group. It is set so that current fluctuation (rise and fall portions) of the initialization current command value of the substantially trapezoidal shape of the accelerator electromagnet power supply 3B related to the second group is performed during the base (see FIG. 13 described later) ). As a result, the output device 16B outputs the initialization pattern (INIT (B), INIT (Q),...) Of the accelerator side command value 18 three times to the accelerator electromagnet power source 3B, and then outputs the normal operation pattern (P1 (B ), P1 (Q), ...). Further, an initialization start command 21 is output from the delay circuit 33 to the output device 17 with a predetermined time delay. The delay time of the delay circuit 33 can also be arbitrarily set. In this embodiment, an appropriate value is set so that the initialization of the electromagnets of the beam transport system 2 is started when the initialization of all the electromagnets of the accelerator 1 is completed. Is set in advance. As a result, the output device 17 outputs the current command values (INIT (HB1), INIT (HQ1),...) For the initialization operation of the transport system command value 19 to the transport system electromagnet power source 4 for three times, and then performs normal operation. Current command values (C1 (HB1), C1 (HQ1), ...) are output.

  When all the initialization operations of the electromagnets of the accelerator 1 and the beam transport system 2 are completed, the accelerator system whole initialization completion signal 25 is issued from the delay circuit 34, and the point of shifting to the start of treatment is the second embodiment described above. , 3 and 4 are the same. However, similarly to the above-described first embodiment, the treatment may be shifted to the start of treatment using the initialization operation completion signal from each of the electromagnet power supplies 3A, 3B, and 4.

  FIG. 13 shows the time change of the current command value output from the control device 5D to the accelerator electromagnet power supplies 3A, 3B and the transport system electromagnet power supply 4 by the function of the sequencer 20D as described above.

  According to the present embodiment described above, the initial stage of the accelerator system electromagnet group 1 (that is, the deflection electromagnet B) and the accelerator system power source stone group 2 (that is, an electromagnet other than the deflection electromagnet B) during the initialization operation using the delay circuit 32. By shifting the start timing, the current change timing of each electromagnet of the accelerator 1 can be positively shifted and leveled, so that disturbance to the power system can be suppressed, thereby reducing the load on the power system. it can.

  In the fifth embodiment described above, the initialization of the electromagnet on the transport system side is performed after the initialization of the electromagnet on the accelerator side is completed. You may make it initialize the electromagnet by the side of an accelerator after completion | finish of initialization. In this case, since the beam transport system 2 can perform initialization on the accelerator side after each electromagnet is in a normal operation with a substantially constant current, the disturbance to the power system can be further reduced.

(Embodiment 6)
FIG. 14 is a diagram schematically showing the internal configuration of the control device 5E of the present embodiment, and corresponds to FIG. 2 and the like of the first embodiment described above. The same parts as those in FIG.

  Since the configuration of the current command values 18 and 19 and the configuration of the output devices 16 and 17 stored in the storage device 15 of the present embodiment are the same as those of the first embodiment, description thereof will be omitted.

  In this embodiment, the initialization start timing of the electromagnet of the accelerator 1 and the electromagnet of the beam transport system 2 is shifted so that the current change does not concentrate on a part. Specifically, as shown in FIG. 14, the delay circuit 35 of the sequencer 20E shifts the input timing of the initialization start command 21 to the output device 16 and the input timing of the initialization start command 21 to the output device 17. In the present embodiment, the delay time by the delay circuit 35 is such that the increase / decrease of the initialization current command value to the transport electromagnet power source 4 (that is, the rising and falling portions of the rectangular wave) is the initialization of the substantially trapezoidal shape of the accelerator electromagnet power source 3. It is set to be performed between flat portions (flat top or flat base) of the current command value (initialization pattern) (see FIG. 15 described later).

  When all the initialization operations of the electromagnets of the accelerator 1 and the beam transport system 2 are completed, the entire accelerator system initialization completion signal 25 is issued from the delay circuit 36, and the point of shifting to the start of treatment is the above-described second embodiment. , 3, 4 and 5. However, similarly to the above-described first embodiment, the start of treatment may be started using the initialization operation completion signal from each of the electromagnet power supplies 3 and 4.

  FIG. 15 shows the time change of the current command value output from the control device 5E to the accelerator electromagnet power source 3 and the transport system electromagnet power source 4 by the function of the sequencer 20E as described above.

  According to this embodiment described above, since the current change timing can be shifted and leveled a total of four times per cycle in the initialization operation of the accelerator electromagnet power source 3 and the transport system electromagnet power source 4, It is possible to prevent disturbances from being concentrated on a part of the waveform period. As a result, the load on the power system can be reduced.

  Although not illustrated one by one, in addition to those already described, the embodiments described above may be used in appropriate combination. For example, in Embodiments 2 to 4, since the power required for initialization on the transport system side is leveled, there is less fear of disturbance to the system, so the initialization of the electromagnets on the accelerator side and the transport system side is performed simultaneously. However, the present invention is not limited to this, and in order to obtain a load reduction effect for a further power system, the power required for the initialization operation on the transport system side is obtained by combining any of Embodiments 1 and 2 to 4. After the leveling and initialization of the transport system side, the initialization on the accelerator side may be performed. Further, for example, it is possible to combine the embodiment 5 and any one of the embodiments 2 to 4 and perform the initialization operation after leveling the electric power necessary for the initialization operation on both the accelerator side and the transport system side. is there.

  In the embodiment described above, the deflector electromagnet B of the synchrotron 7, the quadrupole electromagnet Q, the hexapole electromagnets SX1 to SX3, the steering electromagnets St1 to St7, and the output septum SM2 are included as the electromagnets on the accelerator side. However, the present invention is not limited to this. For example, only the deflection electromagnet B or only the deflection electromagnet B and the quadrupole electromagnet Q may be used. This is because the power required by each of the 6-pole electromagnets SX1 to SX3, 8-pole electromagnets, steering electromagnets St1 to St7, and entrance / exit is negligibly small compared to the deflection electromagnet B and the quadrupole electromagnet Q. Because.

  Furthermore, in the embodiment described above, an example in which the present invention is applied to a particle beam therapy system for treating cancer or the like is shown, but not limited to this, industrial use such as generation of radiation isotopes, material irradiation, The present invention can be applied to an accelerator system used for various purposes such as agricultural use such as seed irradiation.

1 is an overall configuration diagram of a particle beam therapy system which is a preferred embodiment of an accelerator system of the present invention. It is a figure which shows typically the internal structure of the control apparatus shown in FIG. FIG. 3 is a diagram schematically illustrating storage contents of the storage device illustrated in FIG. 2. It is a figure showing the time change of the electric current command value output to a transport system electromagnet power supply and an accelerator electromagnet power supply from a control apparatus. It is a figure which shows typically the internal structure of the control apparatus in 2nd Embodiment of this invention. It is a figure which illustrates typically the memory content of the memory | storage device in 2nd Embodiment of this invention. It is a figure showing the time change of the electric current command value output to the transport system electromagnet power supply and accelerator electromagnet power supply from the control apparatus in 2nd Embodiment of this invention. It is a figure which shows typically the internal structure of the control apparatus in 3rd Embodiment of this invention. It is a figure showing the time change of the electric current command value output to the transport system electromagnet power supply and accelerator electromagnet power supply from the control apparatus in 3rd Embodiment of this invention. It is a figure which shows typically the internal structure of the control apparatus in 4th Embodiment of this invention. It is a figure showing the time change of the electric current command value output to the transport system electromagnet power supply and accelerator electromagnet power supply from the control apparatus in 4th Embodiment of this invention. It is a figure which shows typically the internal structure of the control apparatus in 5th Embodiment of this invention. It is a figure showing the time change of the electric current command value output to the transport system electromagnet power supply and the accelerator electromagnet power supply from the control apparatus in 5th Embodiment of this invention. It is a figure which shows typically the internal structure of the control apparatus in 6th Embodiment of this invention. It is a figure showing the time change of the electric current command value output to the transport system electromagnet power supply and accelerator electromagnet power supply from the control apparatus in 6th Embodiment of this invention.

Explanation of symbols

1 Accelerator 2 Beam transport system 3 Accelerator electromagnet power supply (electromagnet power supply)
3A First accelerator electromagnet power source (electromagnet power source)
3B Second accelerator electromagnet power supply (electromagnet power supply)
4 Transportation electromagnet power supply (electromagnet power supply)
4A First transport system electromagnet power source (electromagnet power source)
4B Second transport system electromagnet power supply (electromagnet power supply)
5 Control Device 5A-5E Control Device 15 Storage Device 16 Output Device 16A-B Output Device 17 Output Device 17A-B Output Device 20 Sequencer (Delay Device)
28 Delay circuit (delay device)
30 Delay circuit (delay device)
32 Delay circuit (delay device)
B Deflection electromagnet (electromagnet)
Q 4-pole electromagnet (electromagnet)
SX1 ~ SX3 6-pole electromagnet (electromagnet)
St1-st7 Steering electromagnet (electromagnet)
HB1-HBn Bending electromagnet (electromagnet)
HQ1-HQn 4-pole electromagnet (electromagnet)
HSt1 ~ HStn Steering electromagnet (electromagnet)

Claims (14)

An accelerator that accelerates a charged particle beam to a set energy;
A beam transport system for transporting the charged particle beam emitted from the accelerator;
An electromagnet power source for exciting an electromagnet provided in the accelerator and the beam transport system;
An accelerator comprising: a control device that controls the electromagnet power supply so that the electromagnet belonging to the accelerator is initialized after the electromagnet belonging to the beam transport system is initialized in the initialization operation. system.   The control device controls the electromagnet power source so that the electromagnet belonging to the accelerator is initialized after the electromagnet belonging to the beam transport system is completed and the operation is performed with a substantially constant excitation current. The accelerator system as claimed in claim 1.   The control device includes a storage device for storing initialization current command information to be output to the electromagnet power source related to the accelerator and the beam transport system, and the electromagnet corresponding to the initialization current command information stored in the storage device. An output device for outputting to the power supply, and delaying the output of the initialization current command information to the electromagnet power source related to the accelerator by the output device after the output of the initialization current command information to the electromagnet power source for the beam transport system The accelerator system according to claim 1, further comprising a delay device to be operated. An accelerator that accelerates a charged particle beam to a set energy;
A beam transport system for transporting the charged particle beam emitted from the accelerator;
An electromagnet power source for exciting an electromagnet provided in the accelerator and the beam transport system;
The electromagnets belonging to the beam transport system are divided into a plurality of groups, and in the initialization operation, the excitation mode for the electromagnets belonging to the beam transport system is changed for each group so that the excitation current of the electromagnets belonging to the beam transport system is changed. An accelerator system comprising: a control device that controls the electromagnet power supply so that a change in total is substantially constant.   The control device includes: a storage device that stores initialization current command information output to an electromagnet power source related to the beam transport system with a phase shift for each group; and an initialization current that is stored in the storage device and has a different phase. The accelerator system according to claim 4, further comprising: an output device that outputs the command information to the electromagnet power source related to the corresponding group.   The control device includes a storage device that stores initialization current command information to be output to an electromagnet power source related to the beam transport system, and an output device that outputs initialization current command information stored in the storage device for each group. 5. The accelerator system according to claim 4, further comprising: a delay device that delays output timing of the initialization current command information by the output device for each group. An accelerator that accelerates a charged particle beam to a set energy;
A beam transport system for transporting the charged particle beam emitted from the accelerator;
An electromagnet power source for exciting an electromagnet provided in the accelerator and the beam transport system;
An accelerator system comprising: a control device that controls the electromagnet power supply so that the electromagnets belonging to the beam transport system are initialized at different times in the initialization operation.   The controller includes a storage device that stores initialization current command information to be output to an electromagnet power source related to the beam transport system, and the electromagnet power source that relates the initialization current command information stored in the storage device to the beam transport system. 8. The accelerator system according to claim 7, further comprising: an output device that outputs each time; and a delay device that delays an output timing of the initialization current command information by the output device for each electromagnet power source. An accelerator that accelerates a charged particle beam to a set energy;
A beam transport system for transporting the charged particle beam emitted from the accelerator;
An electromagnet power source for exciting an electromagnet provided in the accelerator and the beam transport system;
A controller for controlling the electromagnet power supply so as to divide the electromagnets belonging to the accelerator into a plurality of groups and perform initialization of the electromagnets belonging to the accelerator at different time intervals in the initialization operation; Accelerator system characterized by that.   The control device is a storage device that stores initialization current command information to be output to an electromagnet power source related to the accelerator, and an output device that outputs initialization current command information stored in the storage device for each group, The accelerator system according to claim 9, further comprising: a delay device that delays output timing of the initialization current command information by the output device for each group.   The accelerator system according to any one of claims 1 to 10, wherein the control device includes a deflection electromagnet, or the deflection electromagnet and a quadrupole electromagnet, as an electromagnet belonging to the accelerator. .   The said control apparatus controls the said electromagnet power supply so that the exciting current of the said electromagnet may be maximized at least once at the time of the initialization of the said electromagnet. The accelerator system described in. Accelerator for accelerating charged particle beam to set energy, beam transport system for transporting charged particle beam emitted from accelerator, and electromagnet power source for exciting electromagnet provided in accelerator and beam transport system In an operating method of an accelerator system equipped with
A method for operating an accelerator system, comprising: initializing an electromagnet belonging to the accelerator after initializing an electromagnet belonging to the beam transport system.   14. The method of operating an accelerator system according to claim 13, wherein initialization of the electromagnet belonging to the beam transport system is completed and initialization of the electromagnet belonging to the accelerator is performed after a steady operation with a substantially constant excitation current is performed. .

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