JPH03179697A - Position detector device of charged particle - Google Patents

Abstract

PURPOSE:To detect charged particles with high reliability through simple constitution, by installing a plurality of transmission means to transmit a part of the detection signals based on an induced charge from each of a plurality of electrodes, as it is, and the rest part of the detection signals, after it is delayed. CONSTITUTION:A part of the detection signals given to transmission lines 6-9 through a position detector 1 are sent to an adder 24 as they are or after they are delayed by delay cables 21-23, and the divided into three signals by a distributor 25, and the DC compounds of detection signals are extracted through a filter 31, and if it is assumed that the voltages induced and detected in transmission lines 6-9 are V1 to V4, V1+V2+V3+V4 is provided to an output terminal 34. The detection signals inputted to a mixer 29 are mixed into oscillation signals delayed by 90 deg. from an oscillator 14 so that they are taken out as V1-V2+V3-V4 at an output terminal 35 and the detection signals inputted into a mixture 30 are mixed into oscillation signals and V1+V2-V3-V4 is taken out at an output terminal 36 through a filter 33. It is thus possible to determine the position of charged particles from voltage provided to the output terminals 34-36.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a charged particle position detection device that is used, for example, in a circular charged particle accelerator or a particle storage ring device and detects the position of accelerated charged particles, and in particular to a charged particle position detection device that detects the position of accelerated charged particles. The present invention is intended to be used as a charged particle position detection device that can detect the position of particles accurately, with high sensitivity, and at high speed.

[Prior Art] FIG. 5 shows, for example, "IEEE Transactions on Nuclear Science (IEEE Tr.
answers on Nuclear 5ci
ence), Vol.

N5-30. No. 4 (August 1983 issue), No. 2356
~ Tea Yeiri (T, published on page 2358)
1 is a circuit diagram showing a position detector and a signal processing circuit of a conventional charged particle position detection device disclosed in a paper by Ieiri et al.

In the figure, (1) is a position detector used in a particle accelerator such as a circular charged particle accelerator or a particle storage ring device, and detects the position of charged particles passing through a vacuum duct;
2) to (5) are attached to a vacuum duct to constitute a position detector (1), which includes a plurality of (four in this case) electrodes that extract the position of a passing charged particle as an induced charge, and (6) to (9).
) are transmission lines that are electrically connected to the electrodes (2) to (5) and transmit the detection signals detected at each electrode to the subsequent stage, (
10) to (13) are electrically connected to the transmission lines (6> to (9)) and also connected to the oscillator (14), so that when charged particles pass through each electrode (2) to (5), This is a mixer with a filter for extracting the second harmonic component of the pass frequency.

Figures 6 and 7 show the position detector (1) shown in Figure 5.
) and for example ``Proceedings on the Fifth Symposium on Accelerator.''
Science and Technology 4 (Procee)
ding of The 5th Syn+posiu
n+ on 8ccelerator 5science
and Technology No. 154 '156 (
FIG. 1 is a cross-sectional view showing an example of a conventional position detector disclosed in 1984. In the figure, (15) is a pipe forming a vacuum duct or vacuum chamber, and (16) is a trajectory of charged particles.

Figure 8 shows, for example, Katsura Tomotaro (To+mota).
r.

Katsura) and Shinkichi Shibata (Shink
Photon Factory Storage Ring Beam Position Monitoring Device (B
eamPosition Mon1tor for
the Photon Factory Stora
ge Ring), in which (1^) is a position detector, and (17) is a device for extracting a detection signal indicating the position of a charged particle to the outside. BNC connector, (18) is a support guide that supports this BNC connector (17), (19) is a charged particle, and (16^) is the central axis of the charged particle (19).The electrode (2) is a BNC connector. Like the connector (17), it is supported by a support guide (18), and when a charge is induced by the electric field generated around the charged particle (19), this is used as a detection signal indicating the position of the charged particle and sent to the BNC connector (1). Similarly to electrodes (2), electrodes (3) to (5) are also supported by support guides (not shown) and provide detection signals to the BNC connector. (4) is a vacuum chamber that accelerates charged particles; The ground of the BNC connector (1) is shared with the bump (15).

The conventional charged particle position detection device shown in FIGS. 5 to 7 is constructed as described above, and its operating principle is as follows. When a charged particle passes through a position in the trajectory (16) in the vacuum duct, an electric charge is induced in the electrodes (2) to (5) as a function of the distance between each of them and the above-mentioned position, resulting in an induced voltage. is obtained and sent to filter mixers (10) to (13) through transmission lines (6> to (9)) for signal processing. In this case, the induced voltage of the electrode (Vl) to (
V, ) and the fixed coordinate position (x) of the central axis of the charged particle
, (y) is X(C(Vl +V2 V3
V4) yoc (Vl L+V3 V4). This allows each induced voltage (■1) to (■
If we can measure 4>, we can know the positions (x) and (y) of the charged particles. The induced voltages (■1) to (■, ) sent to the mixers with filters (10> to (13)) through the transmission lines (6) to (9) are extracted there as a signal with twice the passing frequency of the charged particles. (x) and (y) are determined from the above equation.

Further, by directly comparing the amount of charge induced in each electrode (2) to (5>), the passing position of the charged particle can be detected.

In the conventional position detector (1^) shown in Fig. 8, charged particles (19) move in a vacuum duct and generate an electric field around them, inducing charges in the electrodes (2) to (5). do.

Here, the voltage as a detection signal generated by the charges induced in these four electrodes (2) to <5> is respectively v.
, ,v2. v3. Let v. Now, as shown in Figure 8, we simulate the motion of a charged particle (19) moving in a vacuum duct, and calculate the x, y coordinates (x), (y) of the charged particle position in the vacuum duct, and the voltage. v, ,v2.
v,,v.

The relationship given by [(V4+Vl)-(V2+V3
)ko: (Vl + V2 + L + V4) and [(Vl+V2)-(V4+V3)koni (Vl
+V2+V3+L) is determined in advance. As a result, the actually measured Vl, V2. The position of the charged particle (19) can be determined from the values of V- and V4 using the calibration curve shown in FIG.

[Problems to be Solved by the Invention] In the conventional charged particle position detection device as shown in Fig. 5, the detection signal G detected by the position detector is transmitted to the subsequent stage via four transmission lines. b) For this reason, there is a problem in that a large number (four in this case) of transmission lines d are generally required. In addition, the signal processing circuit is equipped with multiple mixers with filters corresponding to the transmission lines, so
Individual differences among these elements must be eliminated,
Therefore, there was also the problem that a lot of labor was required.

In addition, there were also problems such as the amount of charge that could be detected decreased due to the rapid change in the sign of the induced charge as the charged particle passed, and the amount of induced charge changed depending on the momentum of the charged particle6. When using a conventional position detector like the one shown in Figure 8, the BNC connector and the vacuum duct are commonly grounded, so the vacuum duct acts as an antenna and picks up noise from the outside, causing noise to reach the BNC connector. There was a problem in that it was easy to mix it into the detection signal. In addition, in such cases, if the amount of charge of the charged particle is small, the detection signal level from the position detector will also be low, and the detection signal will be buried in noise and cannot be detected, resulting in the problem that the position of the charged particle cannot be detected. There was also.

This invention was made in order to solve all of the above-mentioned problems, and it is possible to lead a detection signal detected by the electrode of a position detector and indicating the position of a charged particle to a subsequent stage through a single transmission line. The object of the present invention is to obtain a charged particle position detection device that has a simple configuration, high reliability, and can perform calculations at high speed.

Another object of the present invention is to obtain a charged particle position detection device that can accurately detect the charge amount and position of charged particles.

A further object of the present invention is to obtain a charged particle position detection device that can accurately detect the position of a charged particle even when the amount of charge of the charged particle is small and the level of the detection signal is low.

[Means for Solving the Problems] A charged particle position detection device according to the present invention includes a position detection means that is attached to a vacuum duct through which charged particles pass, and has a plurality of electrodes that extracts the position of the passing charged particles as an induced charge. , a plurality of transmission means for transmitting detection signals based on the induced charges from each of the plurality of electrodes, some of which are transmitted as is and the rest of the signals delayed, and the output signals of these transmission means are added to form a single signal. The device is equipped with an addition means for converting the signal into a signal, and means for extracting, from the output signal of the addition means, a DC component, a fundamental wave component, and a 90° shifted fundamental wave component of a waveform indicating the passage of the charged particle through the electrode. .

The charged particle position detection device according to the present invention also includes a position detection means in which a dielectric is added to the surface of an electrode, or a plurality of position detection means that are attached to a vacuum duct through which the charged particles pass and extract the position of the passing charged particles as an induced charge. position detection means, comprising: electrodes; a connector electrically connected to each of these electrodes to take out its output to the outside and shield the electrodes; and an insulating material that completely floats the connector from the vacuum duct. It is equipped with the following.

The charged particle position detection device according to the present invention is attached to a vacuum duct through which charged particles pass, is doubly shielded, has a dielectric material at its tip, and has a plurality of devices that extract the positions of passing charged particles as induced charges. a position detection means having electrodes, a plurality of transmission means for transmitting a detection signal based on the induced charge from each of the plurality of electrodes, part of which is transmitted as is and the rest delayed, and output signals of these transmission means. , and signal output means for multiplying the output signal of the adding means and a reference signal.

[Function] In this invention, a plurality of detection signals detected by a plurality of electrodes are sent to a subsequent stage as one detection signal, and this one detection signal is calculated at high speed.

Furthermore, since the electrodes of the position detector used in this invention are electrically insulated, a charge proportional to the charge of charged particles passing through the vacuum duct is induced, and since the electrodes are shielded, , the noise is difficult to ride.

[Embodiment] FIG. 1 is a circuit diagram showing an embodiment of the charged particle position detection device according to the present invention, and (1> to (9> and (14>)
is exactly the same as in the conventional device. (21
〉~(23) are position detectors as particle position detection means (
Transmission lines (7) to (9) from electrodes (3) to (5) of 1>
), the delay cable (24) is connected to the transmission line (6) and the delay cables (21> to (23)) and constitutes a delay transmission means together with the transmission lines (7) to <9), and the delay cable (24) is connected to the transmission line (6) and the delay cables (21> to (23)), An adder (25) serves as an adding means for adding four detection signals indicating the position of the adder (24).
〉 is connected to the output side of 〉 and divides the combined detection signal into three. 〉 is an oscillation signal having a fundamental frequency corresponding to the fundamental wave of the detection signal having the electrode passing frequency of charged particles. An oscillator (26) that generates oscillator (14) is connected to this oscillator (14), and a phase shifter (27) adjusts the phase of the oscillation signal from the oscillator (14) with respect to the detection signal from the position detector (1). > is a divider that divides the phase-shifted oscillation signal from this phase shifter (26) into two, and (28) is connected to this divider (26), and this divider (27) and phase shifter ( a delay circuit that delays the phase of the oscillation signal sent from the oscillator (14) by 90° through (28);
) is connected to the distributor (25) and the delay circuit (28), mixes the detection signal from the position detector (1) and the phase-shifted and delayed oscillation signal from the oscillator (14), and generates the detection signal. A mixer (30) is connected to the distributors (25〉 and (27〉) to obtain a 90° delayed fundamental wave component of The mixer that obtains the fundamental wave component of (31) is the distributor (
(25) is a filter that extracts the DC component from the divided detection signal from the mixer (29), (32) is a filter that obtains the 90° delayed fundamental wave component of the detection signal from the mixer (29), and (33)
is a filter that obtains the fundamental wave component of the detection signal from the mixer (30). In addition, among the delay cables (21> to (23)), the signal delay amount of the delay cable (21) is 174 of the passage period of charged particles, and that of the delay cable (22) is 2/4,
The delay cable (23) is 3/4.

In the charged particle position detection device configured in this way, the electrodes (2) to (5) of the position detector (1) are arranged as in the conventional example.
) The position of the charged particle is detected by utilizing the fact that there is a proportional relationship between the detected voltage induced in the field and the position of the charged particle. In other words, the detection signals given to the transmission lines (6) to (9) through the electric fis (2) to (5) of the position detector (1) remain as they are)
, and are each delayed by the delay cables <21) to (23) as described above before being sent to the adder (24). The adder (24) collects the rj and rena detection signals into one, and the distributor (25) divides them into three signals, which are sent to a filter (31), a mixer (29), and a mixer (30>), respectively. The filter (31) extracts the DC component of the detection signal, and converts the voltages induced in the transmission lines (6) to (9) of the position detector (1) to V, , V2゜v, , v
4, V, +V2+v3+v4 becomes the output terminal (3
4〉. Similarly, the detection signal input to the mixer (29) is mixed with the 90° delayed oscillation signal from the oscillator (14), and the output terminal (35) is L-V2+V3-.
It is taken out as V4. Furthermore, the detection signal inputted to the mixer (30) is mixed with the oscillation signal and passed through the filter (33).
), V, +L-V, and -L are taken out to the output terminal (36). The position of the charged particle is determined from the voltages applied to these output terminals (34) to (36) in the same way as in the conventional example.

In the above embodiment, a position detector equipped with an electrode was used, but similar operation can be expected even if other position detectors are used.

In addition, in the above embodiment, four transmission lines were used as signal lines for the detection signal from the position detector, but no matter how many there are, the number of transmission lines can be reduced to one, and the same You can expect it to work.

FIG. 2 is a sectional view showing a position detector that can be used in place of the position detector shown in FIG. The position detector (IB) in Fig. 2 has a dielectric material (37
) is different from the position detector (1) shown in FIGS. 5 to 7. In the position detector (IB) of FIG. 2, when a charged particle passes, it first induces polarization in the dielectric (37). The electric charge induced on the dielectric (37) is added to the electric charge induced on the electrodes (2) to (5) that are in contact with the dielectric (37), and flows out to the transmission line. By integrating this outflow charge, the amount of charge induced in the dielectric (37) can be determined, and therefore the amount of charge of the charged particles passing through the vacuum duct can be determined. Further, the position of the charged particle can also be detected from the above-mentioned induced charge.

FIG. 3 is a sectional view showing a position detector that is an improved version of the conventional position detector shown in FIG. BNC connector (17
) completely floats from the vacuum duct pipe (15). Ceramic is an insulating material that is used as a BNC connector (17).
and the point inserted between the support guide <18>, and the polyelectric 8i! A shield (3
9) is different from the position detector (1^) in FIG. 8.

In the position detector (IC) configured in this way,
The BNC connector (17) is completely suspended from the pipe (15) of the vacuum duct by the ceramics (38), and the shield (39) from the BNC connector (17) extends to the electrode (2) and serves as its ground. Since the noise level is reduced, the signal indicating the position of the charged particle can be detected even if the amount of charge of the charged particle is small.The position of the charged particle is the same as in the conventional example. It can be determined by comparing the simulation plot in the figure with the detection signal voltages v, , v2.v, , v.

Note that the shapes of the electrodes (2) to (5) are not particularly determined, but similar effects can be expected by using electrodes of any shape. Furthermore, although a circular vacuum duct is shown, a similar effect can be expected by using a vacuum duct of any shape.

FIG. 4 is a circuit diagram showing a modification of the present invention, and the position detector (ID) used here has a dielectric material (37
) and doubly shielded electrode (2A) ~
It has (5^). Furthermore, the output signal of the adder (24) and the oscillation signal of the oscillator (14), that is, the reference signal, are different from the output signal of the adder (24).
0) to form a product signal, and this product signal is outputted from an output terminal (42) after being filtered by a filter, for example, a low-pass filter (41). In addition, the multiplier (40〉
and the filter (41) constitute a signal output means.

[Effects of the Invention] As explained in detail above, the present invention includes a position detecting means that is attached to a vacuum duct through which charged particles pass and has a plurality of electrodes that extracts the position of the passing charged particles as an induced charge; A plurality of transmission means for transmitting detection signals based on the induced charge from each of the electrodes, some of which are transmitted as they are, while the rest are delayed, and an addition method that adds the output signals of these transmission means to one signal. and a means for extracting the DC component, the fundamental wave component, and the 90° phase-shifted fundamental wave component of the waveform indicating the passage of the charged particles through the electrodes from the output signal of the adding means, so the configuration is simple and reliable. It has the effect of providing a highly accurate charged particle position detection device,
In addition, position detection means with a dielectric added to the surface of the electrode, or attached to a vacuum duct through which charged particles pass,
A plurality of electrodes extracting the positions of passing charged particles as induced charges, a connector electrically connected to each of these electrodes to extract the output to the outside and shielding the electrodes, and a connector that is completely connected to the vacuum duct. Since the position detection means is equipped with an insulating material floating on the surface, the amount of charge that can be detected increases, and therefore the detection sensitivity increases. In addition, the detection sensitivity is less dependent on the momentum of the charged particles.
Alternatively, even if the charge of the charged particles is small, it is possible to detect a signal above the noise level and the position of the charged particles.In addition, it is attached to a vacuum duct through which the charged particles pass, is double shielded, and has a dielectric material at the tip. a position detecting means having a plurality of electrodes which extract the position of a passing charged particle as an induced charge; and a detection signal based on the induced charge from each of the plurality of electrodes, a part of which is left as it is and the rest of which is delayed. The present invention is equipped with a plurality of transmission means for transmitting the same signal, an addition means for adding together the output signals of these transmission means to form one signal, and a signal output means for multiplying the output signal of the addition means by a reference signal. , it is possible to simplify the large amount of wiring that was conventionally routed between the laboratory and the control room, to detect the position of charged particles at high speed, to reduce noise and perform highly accurate detection, and to transmit signals. 6, which has the effect of being able to detect with high sensitivity

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of this invention, FIGS. 2 and 3 are sectional views showing a position detector used in this invention, and FIG. 4 is a circuit diagram showing a modified example of this invention. , FIG. 5 is a circuit diagram showing a conventional charged particle position detection device, FIGS. 6 to 8 are cross-sectional views showing a conventional position detector, and FIG. 9 is a simulation calibration diagram. In the figure, (1) and (IB) to (ID> are position detectors, (2) to (5) and (28) to (5^) are electrodes, and (6)
~(9) is a transmission line, (15> is a vacuum duct pipe,
(17) is a connector, (19) is a charged particle, (21) ~
(23) is a delay cable (24) is an adder, (28) is a delay circuit, (29) to (3o) are mixers, (31) to (
33) and (41) are filters, (37) is a dielectric, (3
8) is an insulating material, (39) is a shield, and (4o) is a multiplier. In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (4)

[Claims] (1) attached to a vacuum duct through which charged particles pass;
A position detecting means having a plurality of electrodes that extracts the position of a passing charged particle as an induced charge, and a detection signal based on the induced charge from each of the plurality of electrodes, a part of which is transmitted as is and the rest is delayed and transmitted. a plurality of transmission means; an addition means for adding the output signals of these transmission means into one signal; and a DC component and a fundamental wave component of a waveform representing the passage of the charged particles through the electrode from the output signal of the addition means; A charged particle position detection device comprising: means for extracting fundamental wave components phase-shifted by 90 degrees. (2) A charged particle position detection device comprising a position detection means in which a dielectric material is added to the surface of an electrode. (3) attached to a vacuum duct through which charged particles pass;
A plurality of electrodes extracting the positions of passing charged particles as induced charges, a connector electrically connected to each of these electrodes to extract the output to the outside and shielding the electrodes, and a connector that is completely connected to the vacuum duct. A charged particle position detecting device comprising: a position detecting means having an insulating material floating on the charged particle position detecting device. (4) attached to a vacuum duct through which charged particles pass;
a position detecting means having a plurality of electrodes that are double shielded, have a dielectric material at the tip, and extract the position of a passing charged particle as an induced charge, and detection based on the induced charge from each of the plurality of electrodes; A plurality of transmission means for transmitting a part of the signal as it is and the rest with a delay, an addition means for adding the output signals of these transmission means to make one signal, and an output signal of the addition means and a reference signal. A charged particle position detection device characterized by comprising: signal output means for multiplying .