JPH0521200A - Control device of accelerator and accelerator system - Google Patents

Abstract

PURPOSE:To provide a control device of accelerators in which the beams from a linac are injected only to a specific bucket of a synchrotron but not to other unnecessary backets, especially to the buckets at the front side and the rear side of the above specific bucket. CONSTITUTION:High-frequency signals from oscillators 21 to 23 are not input to high-frequency amplifiers 15 to 17 as they are, but input to the amplifiers 15 to 17 after modulating once by modulators 18 to 20. As the modulation signal, a high-frequency signal from the high-frequency accelerator 26 of a synchrotron 2 is used, and it is synchronized with the bucket.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accelerator controller and an accelerator system, and more particularly to a controller for transferring a charged beam between accelerators in an accelerator system in which a plurality of accelerators are combined.

[0002]

2. Description of the Related Art A method of transmitting and receiving a beam between accelerators, in particular,
Various studies have been made on a method of filling a bunch, that is, an electron mass, at a specific position of a bucket on an orbit of a synchrotron or a storage ring. However, the precise transfer of the beam between the linac or linear accelerator and the synchrotron has not been well discussed. References for this type of device include, for example, "Heavy Ion Med.
ical Accelerator in Chiba ”.

[0003]

DISCLOSURE OF THE INVENTION In the prior art,
No particular consideration has been given to bucket selection when the relationship between the frequency of the linac acceleration radio frequency signal and the frequency of the synchrotron acceleration radio frequency signal is not a simple ratio, eg an integer ratio. If the acceleration frequency of the synchrotron is, for example, 500 MHz, the bucket is 2n.
It exists every s. On the other hand, when the acceleration frequency of the linac is 3 GHz, the beam of the linac is 0.33 ns.
It arrives at the synchrotron every time. As described above, since the frequency ratio between the two is not a simple ratio in general, the beam of the linac and the bucket of the synchrotron cannot always be maintained in the same time relationship. As a result, there is a problem that a beam from the linac is made incident on an unnecessary bucket.

An object of the present invention is to provide a control device for an accelerator in which a beam from a linac is incident only on a specific bucket of a synchrotron and not on unnecessary buckets, particularly buckets before and after the specific bucket. Is.

[0005]

In order to achieve the above-mentioned object, the present invention provides an accelerator system including a linac and a synchrotron, wherein a high frequency electric field applied to an accelerating tube of the linac is a high frequency of a high frequency accelerator of the synchrotron. The present invention proposes an accelerator control device having means for modulating with a signal.

The synchrotron is equipped with a bucket selection device that counts the buckets of the synchrotron based on the high frequency signal from the high frequency acceleration device and determines the incident timing of the beam from the linac.

Of course, the oscillation frequencies of the oscillators of the high frequency electric field applied to the linac acceleration tube may be different from each other.

More specifically, the present invention relates to a donut-shaped vacuum duct, a high-frequency cavity arranged in a part of the duct in the circumferential direction, and a high-frequency accelerator for applying a high-frequency signal to the high-frequency cavity and the duct. An injector which is arranged in a part of the circumferential direction and takes in a charged beam accelerated from the outside into a duct, and a bucket selector which controls the injector based on a high frequency signal from the high frequency accelerator to select a bucket for the charged beam A synchrotron, an oscillator that generates a high-frequency signal, a modulator that modulates the high-frequency signal from this oscillator with the high-frequency signal from the high-frequency accelerator, a high-frequency amplifier that amplifies the modulated high-frequency signal, a beam source, and this beam source. Linac including an accelerating tube for accelerating the beam of the laser beam by the electric field of the modulated high frequency signal from the high frequency amplifier and sending the beam to the above-mentioned injector. It is intended to propose the accelerator system to be.

[0009]

[Function] The high-frequency electric field applied to the linac acceleration tube is
It changes at a frequency that corresponds to the velocity of the charged particles that make up the beam. When this high frequency electric field is modulated by the accelerating frequency signal of the synchrotron by the modulator, the beam generated by the beam source of the linac can be accelerated only in the portion corresponding to the bucket of the synchrotron. The means to select a particular bucket of the synchrotron is easy to implement, so
By combining these means, it is possible to obtain an accelerator control device in which the beam from the linac is made incident only on a specific bucket of the synchrotron and is not made incident on unnecessary buckets, particularly buckets before and after the specific bucket.

[0010]

1 is a block diagram showing an example of an accelerator system comprising a linac and a synchrotron equipped with a control device according to the present invention. An accelerator such as a storage ring may be further installed after the linac 1 and the synchrotron 2, but it is not shown here.

The linac 1 is a device for accelerating the electrons or the like generated by the beam source 11 by the accelerating tubes 12 to 14 to make them incident on the synchrotron 2 connected in the subsequent stage. A high frequency electric field from high frequency amplifiers 15 to 17 using a klystron or the like is applied to the acceleration tubes 12 to 13. These high frequency electric fields are obtained by amplifying the high frequency signals of the oscillators 21-23.

The feature of the present invention is that the high frequency signals from the oscillators 21 to 23 are not directly input to the high frequency amplifiers 15 to 17, but are once modulated by the modulators 18 to 20,
The input is to the high frequency amplifiers 15 to 17. A high-frequency signal from the high-frequency accelerator 26 of the synchrotron 2 is used as the modulation signal and is synchronized with the selection of the bucket.

The synchrotron 2 takes in the pulsed beam generated by the linac 1 into the ring-shaped duct 24 through the injection device 27, and by the high frequency cavity 25 to which the high frequency electric field of the high frequency accelerator 26 is applied, The beam is accelerated to a predetermined energy. Synchrotron 2
Has various electromagnets in order to orbit the beam on a predetermined orbit, but it is omitted in the present embodiment. The incidence timing of the incident device 27 is controlled by the bucket selection device 28. This bucket selection device 28
Divides the high frequency signal from the high frequency accelerator 26 and selects the bucket of the synchrotron 2 in synchronization with the signal.

FIG. 2 is a time chart showing an example of the operation of this accelerator system. A shows the state of the beam when the linac 1 is driven. The state A corresponds to the case where the high frequency signal of 3 GHz shown by B from the oscillators 21 to 23 is amplified without being modulated and is used for beam acceleration. On the other hand, C indicates the state of the bucket or the bunched beam of the synchrotron 2, and D indicates the high frequency signal of 500 MHz from the high frequency accelerator 26. E is a 3G shown in B based on the concept of the present invention.
The state where the high frequency signal of Hz is modulated by the high frequency signal of 500 MHz shown in D is shown. F shows the state of the beam of the linac 1 accelerated by the modulation signal of E. That is, since the high frequency electric field applied to the accelerating tubes 12 to 14 of the linac 1 is modulated as E by the modulators 18 to 20, only the beam at the time corresponding to the bucket indicated by C of the synchrotron 2 is Linac 1 like F
Sent out from.

The bucket selection device 28 counts the high frequency waves of the synchrotron 2 to select a specific bucket of the synchrotron 2 and sends an injection command G to the injection device 27. As a result, in the synchrotron 2, the beam can be incident on a predetermined position to form a bunch. As described above, the unnecessary portion before and after the predetermined position in the pulsed continuous beam shown by A is removed by the operation of the injection device 27 according to the G incident command. Further, a small pulse near the pulse at the predetermined position shown by F is absorbed by the bucket of the synchrotron 2 as shown by H, and as a result, only the beam at the predetermined position is obtained.

In this embodiment, the high frequency signals to be applied to the accelerating tubes 12 to 14 of the linac 1 are temporarily modulated by the modulators 18 to 20 by the high frequency signals from the high frequency accelerating device 26 on the synchrotron 2 side. Linac 1
The beam output of the synchrotron 2 can be captured in synchronization with the bucket of the synchrotron 2, and a bunch can be formed only in an arbitrary bucket of the synchrotron 2.

Further, since the high frequency signal from the high frequency accelerating device 26 is counted by the bucket selecting device 28 to generate the incident timing, the incident timing can be determined only by the synchrotron 2, and the synchrotron 2 which is generally long distance. It is possible to reduce the signal transmission line between the linac 1 and the linac 1.

The acceleration frequency of each accelerator can be determined arbitrarily.

[0019]

According to the present invention, since the beam output of the linac can be taken in in synchronization with the bucket of the synchrotron, a bunch can be formed only in any bucket of the synchrotron, and the accelerator can be operated with high precision. Can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an accelerator system including a linac and a synchrotron having a control device according to the present invention.

FIG. 2 is a time chart showing an example of the operation of the accelerator system in FIG.

[Explanation of symbols]

1 linac 2 synchrotron 11 beam source 12-14 Accelerator 15-17 High frequency amplifier 18 to 20 modulator 21-23 oscillator 24 ducts 25 high frequency cavity 26 High-frequency accelerator 27 Injector 28 Bucket selection device

Claims (4)

[Claims] 1. An accelerator system including a linac and a synchrotron, comprising means for modulating a high frequency electric field applied to an accelerating tube of the linac by a high frequency signal of a high frequency accelerating device of the synchrotron. Control device. 2. The accelerator control device according to claim 1, wherein a bucket of the synchrotron is counted based on a high-frequency signal from the high-frequency accelerator of the synchrotron, and an incident timing of a beam from the linac is determined. A control device for an accelerator, comprising: 3. The accelerator control device according to claim 1, wherein the oscillators of the high frequency electric field applied to the linac acceleration tube have different oscillation frequencies. 4. A donut-shaped vacuum duct, a high frequency cavity arranged in a part of the duct in the circumferential direction, a high frequency accelerating device for applying a high frequency signal to the high frequency cavity, and a duct in the circumferential direction of the duct. An injector which is disposed in a part and takes in a charged beam accelerated from the outside into the duct, and a bucket selection device which controls the injector based on a high frequency signal from the high frequency accelerator to select a bucket of the charged beam. A synchrotron that includes a high frequency signal, an oscillator that generates a high frequency signal, a modulator that modulates the high frequency signal from the oscillator with the high frequency signal from the high frequency accelerator, a high frequency amplifier that amplifies the modulated high frequency signal, and a beam source. And an accelerating tube for accelerating the beam from the beam source by the electric field of the modulated high frequency signal from the high frequency amplifier and sending it to the injection device. Accelerator system consisting of a linac, including.