JPH11354300A - Timing control device for particle accelerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the incident/emitting timing of a particle accelerator using a resonance power source. SOLUTION: A timing control device for a particle accelerator is provided with an electric current detecting means 31 or a magnetic flux density detecting means 33 for detecting a sine wave-shaped signal corresponding to a change in a magnetic field of a deflection electromagnet, a cycle signal generating means 23 for outputting a pulse-shaped cycle signal in the vicinity of the minimum value by inputting the sine wave-shaped signal, a cycle signal delay means 25 for adjusting a timing difference in a cycle signal, a synchronous means 27 for outputting a synchronous clock in synchronism with the cycle signal from the cycle signal delay means 25 by inputting a reference clock for outputting a pulse at a rate of a signal pulse when magnetic flux density of the magnetic field of the deflection electromagnet increases by a certain constant quantity and a delay counter 29 for outputting a trigger signal of respective control object apparatuses related to incidence, acceleration and emission according to a preset count value on the basis of a synchronous clock from this synchronous means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timing control device for controlling the operation timing of a controlled device of a particle accelerator for accelerating charged particles such as ions, which needs to operate at high speed, high accuracy and high reproducibility. .

[0002]

2. Description of the Related Art FIG. 18 schematically shows a configuration example of this type of particle accelerator. In this figure, charged particles, for example, ions are output from the injector 1 at a constant energy and pass through the low energy particle transport system 3 to the acceleration ring 5.
It is led to. The ions guided to the acceleration ring 5 are accelerated by the acceleration cavity 7. While being accelerated, the ions are pulled toward the center of the acceleration ring 5 by a magnetic field generated by a plurality of pairs of opposed bending electromagnets 9 and continue to orbit in the acceleration ring 5. When the ions reach a certain energy level as a result of the acceleration, the ions are moved from the acceleration ring 5 to the high-energy particle transport system 13 by the emitter 11, and guided to the utilization system 17 via the emission system magnet 15. In the utilization system 17, the accelerated charged particles (ions) are used for treatment of cancer or the like.

The timing controller outputs an operation trigger to the injector 1, the emitter 11, and the acceleration pattern controller of the acceleration cavity 7 at a predetermined timing, so that ions can be efficiently transmitted to the low energy particle transport system 3, 5 and through the high-energy particle transport system 13 to the utilization system 17. if. If the timing control device does not operate rationally, there occurs a problem that the ions collide with the inner wall of the acceleration ring 5 before being guided to the utilization system 17 and disappear, for example.

The conventional particle accelerator timing control device also controls the timing of the magnetic field strength of the bending electromagnet 9 in synchronization with the timing control of the acceleration pattern control of the injector 1, the emitter 11, and the acceleration cavity 7.

FIG. 19 shows a timing chart of timing control of a conventional timing control device for a particle accelerator. FIG.
In 9, after the ions are made to enter the acceleration ring 5 from the injector 1, the acceleration by the acceleration cavity 7 is started, and the strength of the bending electromagnet 9 starts to increase in synchronization with the acceleration. afterwards,
When the ions reach a certain energy level, the emitter 11 is triggered to reset the acceleration level of the accelerating cavity 7 to the level at the time of the original incidence. To prepare for the next timing control of the incidence, acceleration, and emission.

[0006]

Incidentally, a resonance power supply may be used as a power supply for the bending electromagnet 9 in some cases. Resonant power supplies have the advantage of being smaller and cheaper than conventional power supplies for electromagnets. The current value of the resonance power supply is about 20
It changes to a sinusoidal waveform of about Hz, and the bending electromagnet 9
Produces a sinusoidal wave of about 20 Hz.
At this time, it is impossible to control the operation timing of the bending electromagnet by the timing control device, and rather, it is necessary to follow the operation of the bending electromagnet in order to perform reasonable timing control.

Therefore, when a resonance power supply is used as a power supply for the bending electromagnet 9, the conventional timing control system controls the timing of incidence-acceleration-emission asynchronously with the magnetic field generated by the resonance power supply 9, so that particle However, there arises a problem that the efficiency is extremely deteriorated due to collision with the inner wall of the acceleration ring 5 and disappearing.

The present invention has been made in view of such a point, and provides a timing control apparatus capable of performing reasonable timing control on a device to be controlled by a particle accelerator using a resonance power supply. The purpose is to:

[0009]

That is, according to the first aspect of the present invention, there is provided an injector for injecting charged particles into an acceleration ring, an accelerating means for accelerating the charged particles to predetermined energy, and the charged particles. Each device related to the incidence, acceleration and emission of a particle accelerator including a bending electromagnet that deflects the orbit in the acceleration ring and an emitter that emits the accelerated charged particles from the acceleration ring to a utilization system. In the timing control device for a particle accelerator that controls the operation timing of the particle accelerator, the bending electromagnet is supplied with a current that changes in a sinusoidal manner from an electromagnet power supply, and forms a magnetic field in which the magnetic flux density changes in a sinusoidal manner in accordance with the change in the current. Injecting the charged particles at a timing when the magnetic flux density is near the minimum value, and increasing the magnetic flux density by a predetermined amount from near the minimum value. And the charged particles is the incident timing, characterized in that emit.

According to a second aspect of the present invention, there is provided an injector for injecting charged particles into an acceleration ring, acceleration means for accelerating the charged particles to predetermined energy, and orbiting the charged particles in the acceleration ring. A bending electromagnet to deflect
A timing controller for controlling the operation timing of each device relating to the incidence, acceleration and emission of the particle accelerator having an emitter for emitting the accelerated charged particles from the acceleration ring to a utilization system; An electromagnet is supplied with a current that changes in a sinusoidal manner from an electromagnet power supply, and forms a magnetic field in which the magnetic flux density changes in a sinusoidal manner according to the change in the current, and corresponds to the change in the magnetic field of the deflection electromagnet. Sine wave signal detection means for detecting a sine wave signal, cycle signal output means for inputting the sine wave signal and outputting a pulse cycle signal near a minimum value of the sine wave signal, and a constant magnetic flux density A reference clock that outputs a pulse at a rate of one pulse when the amount increases is output, and a synchronous clock is output in synchronization with the cycle signal. And a trigger signal output means for outputting a trigger signal of each device relating to the incidence, acceleration and emission according to a preset count value based on the synchronization clock. .

According to the first and second aspects of the present invention, it is possible to control the timing of incidence, acceleration, and emission in synchronization with the change in the magnetic field of the bending electromagnet.

According to a third aspect of the present invention, in the timing control device of the second aspect, the set count value changing means for changing the emission count value set in the trigger signal output means according to the use of the utilization system. It is characterized by having.

According to the third aspect of the present invention, the energy of the emitted charged particles can be changed according to the use of the utilization system.

According to a fourth aspect of the present invention, in the timing control device of the second or third aspect, the number of cycle signals output from the cycle signal output means is suppressed to a predetermined number of cycles in accordance with the use of the utilization system. It is characterized by having cycle suppression means.

According to the fourth aspect of the present invention, the amount of the emitted charged particles can be changed according to the use of the utilization system.

According to a fifth aspect of the present invention, in the timing control device according to any one of the second to fourth aspects, the number of cycle signals output from the cycle signal output means and the emission signal set in the trigger signal output means are set. Based on the beam amount set value file and the beam amount set value file in which the combination of the count values is stored in advance by patterning, the combination pattern is selected according to the use of the utilization system, and the combination pattern is output to the utilization system. Beam amount control means for controlling the amount and energy of charged particles.

According to the fifth aspect of the present invention, the pattern of the combination of the number of cycle signals and the count value for emission is prepared in advance according to the use of the utilization system.
The amount and energy of the emitted charged particles can be easily controlled according to the application.

According to a sixth aspect of the present invention, in the timing control device of the fifth aspect, an emission target file in which operation plan information for specifying the combination pattern is registered for each emission target of the utilization system; An operation plan control unit that provides the beam amount control unit with information for selecting the combination pattern according to the operation plan information of the designated emission target in the file.

According to the sixth aspect of the present invention, a pattern defining the amount and energy of the charged particles to be emitted is registered as operation plan information in advance for each object to be emitted. It is also easy to sequentially change the pattern and emit light to the target.

According to a seventh aspect of the present invention, in the timing control device according to any one of the second to sixth aspects, the cycle signal output means inputs the sine wave signal, and the sine wave signal is equal to or less than a threshold value. Cycle signal generating means for outputting a pulse-shaped cycle signal when the cycle signal is generated, and cycle signal delay means for delaying the cycle signal from the cycle signal generating means and outputting the signal at an optimum value near the lowest value of the sinusoidal signal. It is characterized by having.

According to the seventh aspect of the present invention, charged particles can be injected at an optimal timing when the strength of the magnetic field of the bending electromagnet becomes near the minimum value.

According to an eighth aspect of the present invention, in the timing control device according to any one of the second to seventh aspects, the position of the irradiation target portion that fluctuates at a substantially constant rhythm is monitored, and the irradiation target portion is set to a predetermined irradiation position. A permission signal generating means for generating a permission signal when the apparatus is at the position, and a cycle permission means for permitting output of a cycle signal from the cycle signal output means only while the permission signal is being generated. And

According to the eighth aspect of the present invention, even if the irradiation target part fluctuates due to heartbeat or respiration such as the heart or lungs and its surroundings, it is necessary to precisely synchronize the irradiation target part with the heartbeat or respiration. A charged particle beam can be irradiated.

According to a ninth aspect of the present invention, in the timing control device of the eighth aspect, an emitter that transmits a trigger signal for emission from the trigger signal output means to the emitter only while the permission signal is being generated. It is characterized by comprising a synchronization means.

According to the ninth aspect of the present invention, even when the irradiation target part deviates from the irradiation position at the time of the emission, the emission of the charged particles can be stopped, and the irradiation of other parts can be effectively prevented.

According to a tenth aspect of the present invention, there is provided the timing control device according to any one of the second to ninth aspects, wherein the charged particles from the emitter are set in accordance with the emission count value set in the trigger signal output means. And an output magnet control means for calculating the intensity of the magnetic field of the output system magnet for guiding the power to the utilization system and controlling the power supply of the output system magnet.

In the tenth aspect, the magnetic field of the output magnet can be optimally adjusted according to the output energy of the charged particles.

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 18, the operation of the particle accelerator using a resonance power supply as the power supply for the bending electromagnet 9 needs to be based on the magnetic flux density generated by the resonance power supply. That is,
The magnetic flux density changes in the form of a sine wave of about 20 Hz, but ions are incident on the acceleration ring 5 from the low energy particle transport system 3 at a timing when the magnetic flux density is near the minimum value, and the ions are accelerated until reaching the maximum value. It is necessary to control the timing so that the light is emitted from the acceleration ring 5 to the high energy particle transport system 13. Then, at the timing near the next lowest value of the sine wave of 20 Hz, the incidence of the next cycle is started. Therefore, the cycle of incidence-acceleration-emission is repeated at a cycle of about 20 Hz.

The timing control apparatus for a particle accelerator according to the present invention is for rationally performing the above-described timing control.

FIG. 1 shows a first embodiment of a timing control device for a particle accelerator according to the present invention. In this drawing, reference numeral 19 denotes a particle accelerator, and as the controlled devices, the emitting device 11, the emitting system magnet 15, and other controlled devices 21 such as the injector 1 are shown. The main part of this embodiment is a cycle signal generating means 2
3, cycle signal delay means 25, synchronization means 27,
The delay counter 29 outputs pulses according to the timing chart shown in FIG.

As shown in FIG. 2A, the cycle signal generating means 23 inputs a signal substantially proportional to a sinusoidal magnetic flux density of about 20 Hz generated by the bending electromagnet 9, and
As shown in (b), a pulse is output as a cycle signal near the lowest value of the signal.

The cycle signal delay means 25 is shown in FIG.
As shown in (1), the cycle signal from the cycle signal generating means 23 is delayed by a predetermined time t1 to a position corresponding to the optimum value near the minimum value of the sinusoidal signal.

The synchronization means 27 inputs a pulse of a reference clock based on a change in the magnetic field of the bending electromagnet 9 as shown in FIG. 2D, and synchronizes with the output signal from the cycle signal delay means 25. The clock pulse is output as shown in FIG.

As shown in FIG. 2F, the delay counter 29 counts the number of synchronization clock pulses from the synchronization means 27 for a set number of times, and outputs a trigger signal for operating timing of the controlled device. For example, the incident delay counter 29
Outputs the first pulse of the synchronous clock as a trigger signal of the injector 1, and the emission delay counter 29 outputs a pulse corresponding to the set emission count as a trigger signal of the emitter 11.

In this embodiment, in addition to the above-mentioned main parts, a current detecting means 31 and a magnetic flux density detecting means 33 are provided as means for generating an input signal of the cycle signal generating means 23 so as to be selectable. A cycle signal delay adjusting means 35 for adjusting the delay set time t1 of the cycle signal delay means 25 depending on which of the means 31 and the magnetic flux density detecting means 33 is selected.

Further, in the present embodiment, the set count value changing means 37, the cycle suppressing means 39, the beam Amount control means 41, beam amount set value file 43, operation plan control means 45, emission target file 47, operation record file 4
9 is provided.

The set count value changing means 37 changes the set count value of the delay counter 29 based on the emission count from the beam amount control means 41. The cycle suppression unit 39 suppresses the number of output cycles of the cycle signal generation unit 23 based on the number of cycles from the beam amount control unit 41.

The beam amount control means 41 obtains a pattern number matching the beam amount and the energy level required by the utilization system 17 from the operation plan control means 45 and refers to the beam amount set value file 43 to output count and cycle. Determine the number. The beam amount setting value file 43 stores the cycle number and the emission count for each pattern number in advance.

The operation plan control means 45 outputs a pattern number corresponding to the beam amount and the energy level for each application based on the emission target file 47.
And records the result in the operation record file 49 as the operation result. The emission target file 47 stores a pattern number for each application in advance.

Beams of various energy levels pass through the high-energy particle transport system 13. In order for these beams to pass smoothly, the magnetic field strength of the exit system magnet 15 is adjusted according to the energy level of the beam. There is a need. In the present embodiment, in order to solve this problem, an output magnet control unit 51 and an output magnet setting value file 53 are provided.

The emission system magnet control means 51 determines the emission count based on the emission count from the set count value changing means 37.
The magnetic field strength of the emission system magnet 15 is adjusted by calculating the magnetic field strength of the emission system magnet 15 and setting the power source of the emission system magnet 15. Here, by using the output magnet setting file 53 in which the magnetic field intensity of the output system magnet 15 is stored in advance for each output count, the magnetic field intensity of the output system magnet 15 can be easily obtained.

In the utilization system 17, the beam may be used for medical purposes such as irradiating the affected part of a cancer patient with a beam to destroy cancer cells. At this time, only the cancer cells must be irradiated with the beam. When cancer cells are present on a constantly moving organ such as the lung or heart, it is necessary to irradiate a beam only when the irradiation target cancer cells move on the irradiation target.

In order to solve this, the present embodiment is provided with a cycle permitting means 55 and an emitter synchronizing means 57. In addition, a heartbeat signal generating means 59 and a respiratory signal generating means 61 are provided so as to be switchable so as to generate input signals for the cycle permitting means 55 and the emitter synchronizing means 57.

The cycle permitting means 55 outputs a permitting signal which is turned ON only when the irradiation target cancer cell is on the irradiation target, the heartbeat signal generating means 59 or the respiration signal generating means 6.
1 and permits the cycle signal generating means 23 to output a cycle signal only when this signal is ON.

Similarly, the emitter synchronizing means 57 receives the permission signal and passes the trigger signal of the delay counter 29 for the emitter only when the permission signal is ON.

Next, the operation of the present embodiment will be described. The cycle signal generating means 23 outputs from the current detecting means 31 or the magnetic flux density detecting means 33 about 2
A signal as shown in FIG. 2A, which is substantially proportional to the sine wave magnetic flux density of 0 Hz, is inputted, and the cycle signal shown in FIG.
A pulse as shown in (b) is output. This cycle signal indicates a cycle of incidence-acceleration-emission repeated at a cycle of about 20 Hz.

FIG. 3 shows an example of a circuit configuration of the current detecting means 31, and FIG. 4 shows each signal IA, V1B,
The waveform of V1C is shown. As shown in FIG. 3, the current detecting means 31 uses the coil 71 to detect a signal V1B proportional to the differential value of the current ΙA supplied from the power supply 9a for the bending electromagnet to the bending electromagnet 9, and to detect the voltage follower 31a. The signal is input to the integrator 31b through the interface. The output of the integrator 31b is K1
* IA, and the signal V1C finally output from the current detecting means 31 is as follows: V1C = K1 * IA + K2 * V1b. Here, K1 and K2 are constants, and V1b is a variable bias voltage. The bias voltage V1b is applied to the output of the integrator 31b so that the cycle signal generating means 23 can appropriately process the bias voltage.
Is added.

The power supply 9 for the bending electromagnet is
When noise is mixed in the current value supplied by a, a low-pass filter as shown in FIG. 5 includes a current value detecting coil 71 and a current value detecting means 31 as the current value filter 73 shown in FIG. It is also possible to adopt a configuration of inserting between them.

FIG. 6 shows an example of the circuit configuration of the magnetic flux density detecting means 33. FIG. 7 shows the signals BA, V of the circuit shown in FIG.
2B and V2C waveforms are shown. The magnetic flux density detecting means 33 is shown in FIG.
The signal V2 proportional to the differential value of the magnetic flux density BA of the magnetic field generated by the bending electromagnet 9 using the coil 75 as shown in FIG.
B is detected and input to the integrator 33b via the voltage follower 33a. The output of the integrator 33b is K3 * BA
And the final output V2C is as follows: V2C = K3 * BA + K4 * Vb. Here, K3 and K4 are constants, and Vb is a variable bias voltage. A bias voltage is applied to the output of the integrator 33b so that the cycle signal generating means 23 can appropriately process the bias voltage.

When noise is mixed in the magnetic flux density detection value of the magnetic field generated by the bending electromagnet 9, a low pass filter as shown in FIG. It is also possible to adopt a configuration of being inserted between the magnetic flux density detecting means 33.

FIG. 8 shows an example of the configuration of the cycle signal generating means 23. FIG. 9 shows a signal processing process in the cycle signal generating means 23. In FIG. 8, the cycle signal generating means 23 includes a comparator 23a and a mono-multi 2
3b.

The comparator 23a receives the reference voltage Vref and the output from the current value detecting means 31 or the magnetic flux density detecting means 33, that is, a signal Vc of approximately 20 Hz sinusoidal wave, as shown in FIGS. 9 (a) and 9 (b). Then, a pulse signal which is turned ON only when the 20 Hz sine wave signal Vc is lower than the reference voltage Vref is output.

As shown in FIG. 9 (c), the mono multi 23b adjusts the pulse width of the pulse signal to a constant width and outputs it as a cycle signal. A gate is inserted in the output stage of the mono-multi 23 b, and the opening and closing of the gate is controlled by the cycle suppressing means 39. Thereby, the cycle suppressing unit 39 can suppress the delay counter 29 from outputting the trigger signal.

By the way, as shown in FIG. 9C, the cycle signal is output t2 seconds before the 20 Hz sine wave has the minimum value. Further, there is a slight difference in timing between the case where the cycle signal is generated from the detected value of the magnetic flux density and the case where the cycle signal is generated from the detected value of the power supply current of the bending electromagnet 9.
A cycle signal delay unit 25 and a cycle signal delay adjustment unit 35 are provided to correct a timing shift when the cycle signal and the 20 Hz sine wave have the lowest value and a timing shift when the cycle signal generation source changes. I have.

That is, the cycle signal delay means 25
As shown in FIG. 2C, a pulse is output after a time t1 second set by the cycle signal delay adjusting means 35 after the input of the cycle signal.

The cycle signal delay adjusting means 35 stores in advance a set time when the cycle signal is generated from the detected value of the magnetic flux density and a set time when the cycle signal is generated from the detected current value of the bending electromagnet power supply. The set time t1 is determined according to what the signal is made from and set in the cycle signal delay means 25.

The synchronization means 27 is provided with a reference clock (FIG. 2).
(D)), and outputs a synchronous clock synchronized with the cycle signal from the cycle signal delay means 25 as shown in FIG.

The reference clock is usually output at a rate of one pulse when the magnetic flux density increases by a certain amount, and no pulse is output when the reference clock decreases. By counting this reference clock, a change in the strength of the magnetic field can be detected. The change in the strength of the magnetic field indicates the increment of energy applied to the particle, that is, by counting this reference clock, the increment of energy applied to the particle can be known.

The delay counter 29 inputs a synchronization clock synchronized with the cycle signal by the synchronization means 27, and outputs a trigger signal when a synchronization clock having the same number C1 (FIG. 2 (e)) as the set count value is input. Then, it resets itself and the synchronization means 27 to prepare for the output of a trigger signal in the next cycle.

Therefore, by appropriately setting the count value of the delay counter 29, it is possible to input and output ions at a desired energy level. Normally, the ion injection timing is preferably when the magnetic field strength of the bending electromagnet is the lowest. Therefore, when the first pulse of the synchronous clock is input, an injection trigger signal is output.

The count value set in the delay counter 29 is changed by the set count value changing means 37.

The number of trigger signals, that is, the number of cycles of the cycle signal is controlled by the cycle suppression means 39. In other words, by suppressing the number of cycles to an appropriate number by the cycle suppressing means 39, the utilization system 1
The required amount of the beam at 7 can be guided to the utilization system 17 through an incident-acceleration-emission process.

The set count value changing means 37 and the cycle suppressing means 39 are provided by the beam amount control means 41
7, the information of the emission count and the cycle number according to the application is received.

The beam amount control means 41 determines the number of cycles and the emission count with reference to the beam amount set value file 43 according to the intended use, and outputs them to the cycle suppression means 39 and the set count value changing means 37, respectively. hand,
Cycle suppressing means 39 and set count value changing means 3
Control the amount and energy of the beam via 7.

FIG. 10 shows an example of the data structure of the beam amount setting value file 43.
Stores the cycle number and the emission count for each pattern number. The cycle number indicates the number of incident-acceleration-emission cycles, and can thereby define the amount of the beam guided to the utilization system 17. The emission count indicates a set count value of the delay counter 29 for the emitter, which can define an energy level for accelerating the beam. Therefore, the beam amount setting value file 43
Is equivalent to storing combinations of various beam amounts and beam energies with pattern numbers.

Therefore, the beam amount control means 41 is given a pattern number according to the intended use,
The number of cycles and the emission count instructed to the cycle suppression means 39 and the set count value changing means 37 can be determined based on the beam amount setting value file 43.

In the utilization system 17, it is necessary to change the beam amount and the energy level according to the application.
In some applications, the amount and energy of the beam may be changed sequentially. In order to facilitate this, an operation plan control unit 45 is provided for sequentially giving a pattern number corresponding to the beam amount and the energy level to the beam amount control unit 41 for each application.

The beam amount control means 41 sends the set count value relating to the energy level corresponding to the given pattern number to the set count value changing means 37 as described above.
The number of cycles related to the beam amount corresponding to the pattern number is loaded to the cycle suppression means 39. The beam amount control means 41 repeats this operation each time a pattern number is given from the operation plan control means 45.

The operation plan control means 45 quickly assigns a pattern number to the beam amount control means 4 for many applications.
It is necessary to give to 1. At this time, it is convenient that a combination of pattern numbers is stored in advance in the emission target file 47 for each application, and necessary pattern numbers can be sequentially extracted from the emission target file 47.

FIG. 11 shows an example of the data structure of the emission target file 47. The emission target file 47 irradiates a patient to be irradiated with a beam and the patient in any number of patterns for use. This indicates that the information is composed of information indicating whether the pattern number is such. For example, for patient A, the type of pattern number is 3
This indicates that the patient A is irradiated with the pattern numbers 2, 5, and 4 in this order.

Further, in formulating an operation plan, it is convenient to record the results of what kind of beam was used in the utilization system 17. Therefore, the operation plan control means 4
5 records the operation result in the operation result record file 49 as shown in FIG. In FIG. 12, the data configuration of the operation result record file 49 is the same as the configuration of the emission target file 47 with the date of irradiation added.

In the above configuration, the operation plan control means 45
Transmits the pattern number to the beam amount control means 41 based on the emission target file 47, and the beam amount control means 41
, The number of cycles and the emission count corresponding to the beam amount and beam energy required by the utilization system 17 are determined, and are notified to the cycle suppression means 39 and the set count value changing means 37, respectively.

The set count value changing means 37 loads the emission count specified by the beam amount control means 41 to the delay counter 29 and changes the set count value.
That is, the energy is accelerated to the energy level required by the utilization system 17.

The cycle suppression means 39 monitors the output state of the cycle signal from the cycle signal generation means 23 based on the number of cycles specified by the beam amount control means 41, and the cycle signals are generated for the specified number of cycles. Then, the gate in the cycle signal generating means 23 shown in FIG. 8 is opened to suppress the output of the cycle signal. That is, the amount of beam required by the utilization system 17 is guided to the utilization system 17 through the process of incidence-acceleration-emission.

In the case where the beam irradiation target is a patient having cancer cells on a constantly moving organ such as the lung or heart, the beam is irradiated only when the irradiation target cancer cells move on the irradiation target. Need to be irradiated. In this case, the cycle signal generating means 23
5. Generate a cycle signal only while allowed by 5.

When the irradiation target is the heart, the cycle permitting unit 55 receives the cancer cells from the heartbeat signal generating unit 59, and when the irradiation target is the lungs, from the respiration signal generating unit 61. Only when the permission signal is ON, the cycle signal generating means 23 is permitted to output the cycle signal.

Similarly, the emitter synchronizing means 57 receives from the heartbeat signal generating means 59 or the respiratory signal generating means 61 a permission signal which is turned ON only when the cancer cell to be irradiated is on the irradiation target. The trigger signal from the delay counter 29 for the emitter is transmitted to the emitter 11 only when is ON. When the permission signal is ON at the time of incidence and OFF at the time of emission in the process of incidence-acceleration-emission, ions incident and accelerated are high in the emitter 11 in FIG. Instead of being emitted to the energetic particle transport system 13, the light is discharged from the acceleration ring 5 to the outside by a discharge unit (not shown).

FIG. 13 shows a timing chart of the permission signal when the affected part is a heart. In the case of a portion that varies with the heartbeat such as the heart or its surroundings, it is assumed that the permission signal is synchronized with the heartbeat. As shown in FIG. 13A, the heartbeat signal can be detected from the body surface as an electric signal. The heartbeat signal generating means 59 inputs a heartbeat signal detected from the body surface, and when the heartbeat signal exceeds a predetermined threshold, the heartbeat signal is generated as shown in FIG.
A permission signal as shown in FIG.

The heartbeat signal generating means 59 can be constituted by, for example, a circuit as shown in FIG. In FIG. 14, a heartbeat signal generating means 59 converts a heartbeat signal into a pulse signal by a comparator 59a, and uses a pulse width by a mono-multi 59b for a time t3 (see FIG. 13 (b)) when an affected part is considered to be present on an irradiation target. Prolong. FIG. 13C shows a sine wave signal of about 20 Hz input to the cycle signal generating means 23, and the permission signal is ON.
Indicates that only the cycle signal corresponding to the time t3 can be input and output.

FIG. 15 is a timing chart of a permission signal when the affected part is a lung. In the case of a part which fluctuates due to respiration in or around the lung, the lung contracts due to respiration. Attach strain gauge around chest. When the lung is inflated, the strain gauge is extended and the resistance increases, and when the lung contracts, the resistance decreases. Therefore, the contraction of the lung can be detected from the change in the resistance value.

The respiratory signal generating means 61 is composed of, for example, a comparator as shown in FIG. 16, and inputs a voltage value on a resistance wire obtained by flowing a constant current through a strain gauge as shown in FIG. Then, when the voltage value is equal to or higher than a predetermined threshold value, an enable signal as shown in FIG. FIG. 15C shows the cycle signal generating means 23.
Indicates an approximately 20 Hz sine wave signal which is input. The output magnet control means 51 inputs the same output count as that loaded into the output delay counter 29 from the set count value changing means 37, and outputs The magnetic field intensity of the output magnet 15 is calculated such that the beam emitted from the 11 passes through the high-energy particle transport system 13 smoothly, and is set as the power source of the output magnet 15. Thereby, the magnetic field intensity of the output system magnet 15 can be adjusted according to the energy level of the output beam.

At this time, the output magnet control means 51
Output magnet setting value file 53 as shown in FIG.
And by taking in the magnetic field strength stored therein, the magnetic field strength according to the energy level of the beam can be obtained in a short time.

In FIG. 17, the output magnet set value file 53 stores a set voltage value for the power source of a plurality of output magnets 15 for every 50 emission counts, ie, every 50 counts of the set value count value of the delay counter 29. I have. In this case, when the emission count from the setting count value changing unit 37 is not specified in the emission system magnet setting value file 53, data specified before and after that is extracted from the emission system magnet setting value file 53, A method of obtaining a set voltage value by interpolation calculation can be adopted.

As is clear from the above description, according to the present embodiment, even when a resonance power supply is used as the power supply for the bending electromagnet, the particles can be synchronized with the changing cycle of the magnetic field of the bending electromagnet at the optimum timing. It is possible to control the operation of inputting, accelerating and outputting the accelerator.

Further, the amount and energy of the emitted charged particles can be easily changed according to the application.

Further, even when the irradiation target is a part that fluctuates due to heartbeat or respiration, the charged particle beam can be accurately emitted only to the irradiation target part.

[0088]

As described above, according to the present invention, even when a power supply having a variable current value, such as a resonance power supply, is used as the power supply for the bending electromagnet, the power supply can be synchronized with the change cycle of the magnetic field of the bending electromagnet. Thus, the operation timing of the incidence, acceleration and emission of the particle accelerator can be controlled.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a timing control device for a particle accelerator according to the present invention.

FIG. 2 is a timing chart illustrating a basic operation of the timing control device shown in FIG.

FIG. 3 is a circuit diagram showing a configuration example of a current detection unit 31 shown in FIG.

4 is a diagram showing waveforms of signals IA, V1B and V1C of the circuit shown in FIG.

5 is a diagram showing a low-pass filter used as a current value filter or a magnetic flux density value filter shown in FIG.

FIG. 6 is a circuit diagram showing a configuration example of a magnetic flux density detection unit 33 shown in FIG. 1;

FIG. 7 is a diagram showing waveforms of signals BA, V2B, and V2C of the circuit shown in FIG. 6;

FIG. 8 is a circuit diagram showing a configuration example of a cycle signal generation unit shown in FIG. 1;

9 is a diagram showing a signal processing process in the circuit shown in FIG.

FIG. 10 is a diagram illustrating an example of a data configuration of a beam amount setting value file illustrated in FIG. 1;

11 is a diagram illustrating an example of a data configuration of an emission target file illustrated in FIG. 1. FIG.

12 is a diagram showing a data configuration example of an operation result record file shown in FIG.

FIG. 13 is a timing chart illustrating generation of a permission signal when the affected part is a heart.

FIG. 14 is a circuit diagram showing a configuration example of a heartbeat signal generation unit shown in FIG. 1;

FIG. 15 is a timing chart showing generation of a permission signal when the affected part is a lung.

FIG. 16 is a circuit diagram illustrating a configuration example of a respiratory signal generation unit illustrated in FIG. 1;

FIG. 17 is a diagram showing a data configuration example of an output magnet setting value file shown in FIG. 1;

FIG. 18 is a diagram schematically showing a configuration of a particle accelerator.

FIG. 19 is a time chart illustrating timing control of a conventional particle accelerator.

[Explanation of symbols]

 11 ... Ejector 15 ... Emission magnet 19 ... Particle accelerator 23 ... Cycle signal generation means 25 ... Cycle signal delay means 27 ... Synchronization means 29 ... Delay counter 31 ... ... Current detecting means 33 ... Flux density detecting means 35 ... Cycle signal delay adjusting means 37 ... Set count value changing means 39 ... Cycle suppressing means 41 ... Beam amount controlling means 43 ... Beam Amount set value file 45 Operation plan control means 47 Target emission file 49 Operation record file 51 Output magnet control means 53 Output magnet setting file 55 Cycle permission Means 57 Detector synchronization means 59 Heart rate signal generating means 61 Respiratory signal generating means

Claims (10)

[Claims] 1. An injector for injecting charged particles into an acceleration ring, an accelerating means for accelerating the charged particles to predetermined energy, and a deflection device for deflecting the charged particles so as to orbit in the acceleration ring. In the timing control device of the particle accelerator for controlling the operation timing of each device related to the incidence, acceleration and emission of the particle accelerator including the electromagnet and the emitter for emitting the accelerated charged particles from the acceleration ring to the utilization system. The deflection electromagnet is supplied with a current value that changes in a sinusoidal manner from an electromagnet power supply, and forms a magnetic field in which the magnetic flux density changes in a sinusoidal manner in accordance with the change in the current, wherein the magnetic flux density has a minimum value. The charged particles are made incident at a timing near, and the charged particles are made incident at a timing at which the magnetic flux density increases by a predetermined amount from around the minimum value. Timing control system for particle accelerator, characterized in that to Isa. 2. An injector for injecting charged particles into an acceleration ring, an accelerating means for accelerating the charged particles to a predetermined energy, and a deflection unit for deflecting the charged particles so as to orbit in the acceleration ring. In the timing control device of the particle accelerator for controlling the operation timing of each device related to the incidence, acceleration and emission of the particle accelerator including the electromagnet and the emitter for emitting the accelerated charged particles from the acceleration ring to the utilization system. The deflection electromagnet is supplied with a current that changes in a sinusoidal manner from an electromagnet power supply, and forms a magnetic field in which the magnetic flux density changes in a sinusoidal manner in accordance with the change in the current. A sine-wave signal detecting means for detecting a sine-wave signal corresponding to the sine-wave signal; Cycle signal output means for outputting a clock signal; and a reference clock for outputting a pulse at a rate of one pulse when the magnetic flux density increases by a certain amount, and outputting a synchronous clock in synchronization with the cycle signal. And a trigger signal output means for outputting a trigger signal of each device relating to the incidence, acceleration, and emission according to a preset count value based on the synchronization clock. Particle accelerator timing controller. 3. The particle accelerator according to claim 2, further comprising a set count value changing unit for changing an emission count value set in the trigger signal output unit according to a use of the utilization system. Timing control device. 4. A cycle suppressing means for suppressing the number of cycle signals output from said cycle signal output means to a predetermined number of cycles according to the use of said utilization system. A timing control device for the particle accelerator according to the above. 5. A beam amount setting value file in which a combination of the number of cycle signals output from the cycle signal output unit and an emission count value set in the trigger signal output unit is stored in a pattern and stored in advance. Beam amount control means for selecting the combination pattern in accordance with the use of the utilization system based on the setting value file and controlling the amount and energy of the charged particles emitted to the utilization system. The timing control apparatus for a particle accelerator according to any one of claims 2 to 4, wherein 6. An emission target file in which operation plan information specifying the combination pattern is registered for each emission target of the utilization system, and according to the operation target information of the designated emission target in the emission target file. The timing control device for a particle accelerator according to claim 5, further comprising an operation plan control unit that provides the beam amount control unit with information for selecting the combination pattern. 7. A cycle signal generating means for receiving the sine-wave signal and outputting a pulse-like cycle signal when the sine-wave signal becomes equal to or less than a threshold value; The particle according to any one of claims 2 to 6, further comprising: a cycle signal delay unit that delays a cycle signal from the generation unit and outputs the signal at an optimum value near a minimum value of the sinusoidal signal. Accelerator timing controller. 8. A permission signal generating means for monitoring a position of an irradiation target portion which fluctuates at a substantially constant rhythm, and generating a permission signal when the irradiation target portion is at a predetermined irradiation position, and generating the permission signal. 8. A timing control device for a particle accelerator according to claim 2, further comprising: a cycle permission unit that permits the output of the cycle signal from the cycle signal output unit only during the operation. . 9. An emitter synchronizing means for transmitting an emission trigger signal from the trigger signal output means to the emitter only while the permission signal is being generated. Particle accelerator timing controller. 10. The intensity of a magnetic field of an emission system magnet for guiding charged particles from the emitter to the utilization system is calculated in accordance with an emission count value set in the trigger signal output means. The timing control device for a particle accelerator according to any one of claims 2 to 9, further comprising an output magnet control means for controlling a power supply of the system magnet.