WO2012081070A1 - Method for making beam incident to charged particle storage ring and system therefor - Google Patents
Method for making beam incident to charged particle storage ring and system therefor Download PDFInfo
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- WO2012081070A1 WO2012081070A1 PCT/JP2010/072367 JP2010072367W WO2012081070A1 WO 2012081070 A1 WO2012081070 A1 WO 2012081070A1 JP 2010072367 W JP2010072367 W JP 2010072367W WO 2012081070 A1 WO2012081070 A1 WO 2012081070A1
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H7/00—Details of devices of the types covered by groups H05H9/00, H05H11/00, H05H13/00
- H05H7/08—Arrangements for injecting particles into orbits
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H13/00—Magnetic resonance accelerators; Cyclotrons
- H05H13/04—Synchrotrons
Definitions
- the present invention relates to a method and system for injecting a charged particle beam into a storage ring that circulates and accumulates charged particles such as electrons.
- a perturbation is generated on the orbit using a perturbation device such as a perturbator, and charged particles incident on the charged particle orbiting device are taken into a stable orbit. . After being taken into the stable orbit, charged particles that orbit the stable orbit may be accelerated using a high-frequency acceleration cavity disposed in the stable orbit.
- a Miracle-type synchrotron radiation generator is known as a synchrotron radiation generator (X-ray generator) using an electron storage ring.
- the Miracle-type synchrotron radiation generator is a compact synchrotron radiation generator using a weakly focused synchrotron.
- a perturbator is used to inject electrons accelerated by a microtron into a storage ring and place the incident electrons on a circular orbit. That is, a sine half-wave current (hereinafter also referred to as an excitation current) is passed through a coil constituting the perturbator to generate a pulse perturbation magnetic field, and circulates incident electrons.
- the excitation current of the sine half wave is repeatedly applied at a constant period (for example, 1 ms (frequency 1 kHz)), and every time the excitation current is applied, incident electrons are taken into the orbit and accumulated, that is, accumulated.
- the current increases.
- the width of the excitation current that is a sine half wave is about 150 ns
- the timing window (beam current width) in which electrons can be incident is about 100 ns.
- a sine half wave is used for the excitation current of the perturbator. This is because when the excitation current flows through the perturbator as a continuous sine wave, the electrons once taken into the orbit are affected by the negative part of the excitation current (current in the reverse direction). It was because it was thought that it could not be made.
- the present invention provides a beam injection method and system for a charged particle storage ring that can easily control the timing of beam injection without using a sine half-wave and can store a larger current than conventional ones.
- the purpose is to do.
- the beam injection method to the charged particle storage ring according to the present invention is a method in which a charged particle beam is incident on a storage ring that circulates charged particles incident from the outside by a perturbation device, and the current intensity is a sine wave in the perturbation device.
- a charged particle beam is incident on the storage ring in a state in which a current that changes in (1) is continuously supplied.
- the time for continuously passing the current through the perturbation device is a time that is at least twice the period of the sine wave.
- the charged particle beam is incident on the charged particle storage ring for a time longer than twice the period of the sine wave.
- a charged particle storage system includes a storage ring that circulates charged particles incident from the outside by a perturbation device, a power source that supplies a current to the perturbation device, and a charged particle beam generation device, and the power source includes the perturbation device.
- the charged particle beam generating apparatus makes the generated charged particle beam incident on the storage ring in a state where a current whose current intensity changes with a sine wave is continuously supplied.
- a charged particle beam is incident on the storage ring in a state where a continuous sine wave excitation current is passed through the perturbation device, whereby a larger current than in the conventional case can be stored in the storage ring. Therefore, when the storage ring is used as an X-ray generator, the X-ray intensity can be increased as compared with the conventional case.
- a device for generating a sine half-wave excitation current which was conventionally necessary, is not necessary.
- charged particles can be taken in every period (one wavelength) of the exciting current which is a continuous sine wave, and therefore, in proportion to the number of sine wave peaks included in the beam current width, X
- the line strength can be increased. For example, if a continuous sine wave having a period of 300 ns is used as the excitation current and the beam current width is 6 ⁇ s (20 times the period of the excitation current), the X-ray intensity is 20 times.
- FIG. 1 is a diagram showing a schematic configuration of a charged particle accumulation system according to an embodiment of the present invention. It is a figure which shows typically the timing of the incident beam and the excitation current of a perturbator in the beam injection method to the charged particle storage ring concerning this Embodiment. It is a circuit diagram which shows the internal structure of the perturbator pulse power supply of FIG. It is a graph which shows the beam current waveform used in experiment, and the excitation current waveform of a perturbator. It is a graph which shows the beam current waveform used in experiment, and the excitation current waveform of a perturbator.
- the charged particle storage system is a system for storing electrons, and includes an electron beam generation unit, a storage ring unit using a weakly focused synchrotron, and a control unit.
- a microtron can be used for the electron beam generator.
- the electron beam generation unit includes a microtron main body 100, a beam extraction unit 102, an RF guide 104, an acceleration cavity 108, an emitter (electron gun) 110, a reference high-frequency oscillator 120, a preamplifier 122, a high voltage pulse power source. 124 and a pulse klystron 126.
- the storage ring unit includes a storage ring main body 200, a beam incident unit 202, a perturbator 204, an acceleration cavity 206, a synchrotron radiation extraction unit 208, and a perturbator pulse power source 220.
- the control unit includes a trigger pulse oscillator 300 that generates a pulse signal for controlling the operation timing of each part of the charged particle accumulation system.
- the microtron main body 100 and the storage ring main body 200 are equipped with known components necessary for functioning as a microtron and a storage ring, respectively.
- the reference high frequency oscillator 120 generates a reference high frequency signal (microwave) having a predetermined amplitude and a predetermined frequency and outputs the reference high frequency signal to the preamplifier 122.
- the reference high-frequency oscillator 120 continuously outputs, for example, a 10 mW reference signal.
- the preamplifier 122 amplifies the high frequency signal input from the reference high frequency oscillator 120 and outputs it to the pulse klystron 126.
- the preamplifier 122 is, for example, a klystron front-stage high-frequency gate amplifier with a maximum output of 1000 W.
- the preamplifier 122 outputs a signal obtained by amplifying the input signal for a predetermined period according to the pulse signal input from the trigger pulse oscillator 300.
- the preamplifier 122 uses a pulse signal output from the trigger pulse oscillator 300 as an output gate pulse.
- the high voltage pulse power supply 124 is a modulator power supply for a pulse klystron.
- the high voltage pulse power supply 124 receives the pulse signal from the trigger pulse oscillator 300 and outputs a high voltage pulse to the pulse klystron 126.
- the pulse klystron 126 speed-modulates electrons generated by the high voltage pulse from the high voltage pulse power supply 124 with a high frequency signal (microwave) input from the preamplifier 122 to generate a high power microwave.
- the generated microwave is output to the RF guide 104.
- the RF guide 104 propagates the microwave to the emitter (electron gun) 110. Since pulse klystrons are well known to those skilled in the art, further description will not be repeated.
- a high frequency electric field is formed in the acceleration cavity 108 by the microwave propagated through the RF guide 104.
- the emitter (electron gun) 110 is heated to emit electrons, the emitted electrons are accelerated by a high-frequency electric field. Since a uniform static magnetic field is formed in a predetermined direction inside the microtron main body 100, the trajectory of emitted electrons becomes an arc shape by the static magnetic field.
- the electrons are output from the beam extraction unit 102 as a linear electron beam 312. Since electron guns are well known to those skilled in the art, further description will not be repeated.
- the electron beam 312 output from the microtron main body 100 is incident on the storage ring main body 200 from the beam incident portion 202. Since a uniform static magnetic field is formed in a predetermined direction inside the storage ring main body 200, the trajectory of the electron beam is bent in an arc shape. The electrons that have passed through the circular arc trajectory enter the perturbator 204. At this time, a predetermined current is supplied from the perturbator pulse power source 220 to the perturbator 204, and a perturbation magnetic field is formed. The electrons are perturbed by this electromagnetic field, the trajectory is corrected, and the electrons travel on a predetermined orbit 314. Thereafter, the circulating electrons are accelerated by the acceleration cavity 206 as necessary. It should be noted that the electrons that did not get on the circular orbit 314 collide with the wall of the storage ring main body 200 or the like like the orbit 316 and disappear.
- the electron beam 312 is emitted from the microtron unit in a state where a continuous sine wave excitation current is supplied to the perturbator 204.
- beam current width For a period of time (beam current width) enters the storage ring main body 200. That is, conventionally, only a current in one direction (positive direction) flows through the perturbator, but in this embodiment, a current flows in both directions (positive and negative directions).
- Electrons incident on the storage ring body 200 that is, a beam current, are supplied at a substantially constant value for a time longer than one cycle of the exciting current that is a sine wave.
- a part of the beam current indicated by symbol A in the beam current of FIG. 3 is perturbed by the perturbator 204 and taken into the orbit 314.
- the beam current (electrons) other than the portion indicated by the reference symbol A is not taken into the circular orbit 314 but hits the wall and disappears.
- the excitation current of a sine wave that continues for a predetermined time is supplied to the perturbator and the electrons are incident for a predetermined time (beam current width) during that period, the number of circulating electrons, that is, accumulation is repeated. Current is increased.
- a perturbator pulse power supply 220 includes a control signal generator 400, four MOS-FETs (hereinafter simply referred to as FETs) 402, 404, 406, 408, a DC power supply 410, a resonance capacitor 412, And a damping resistor 414.
- the inductor 416 in FIG. 4 represents a coil that forms the perturbator 204.
- the circuit formed by the four FETs 402, 404, 406, and 408 is connected to the power source 410, the resonance capacitor 412, and the inductor 416 via the four terminals 420, 422, 424, and 426.
- a predetermined excitation current is supplied from the perturbator pulse power supply 220 to the inductor 416 (perturbator).
- the inductance of the perturbator 204 is, for example, 150 nH.
- the DC power supply supplies, for example, DC 300 V and 50 kW.
- the control signal generator 400 applies a control voltage to the gates of the four FETs 402, 404, 406, and 408 at a predetermined timing for a predetermined time using the pulse signal input from the trigger pulse oscillator 300 as a trigger.
- An example of the control voltage is shown in FIG. FIG. 3 shows the control voltage applied to the gate of each FET on the same time axis as the sine wave excitation current.
- the cycle of the control voltage is the same as the cycle of the excitation current.
- FIG. 3 when a high level voltage is applied to the FETs 402 and 408, a low level voltage is applied to the FETs 404 and 406.
- the experimental results are shown below.
- an existing storage ring device “MIRRORCLE-CV4 manufactured by Photon Generation Technology Laboratory Co., Ltd.
- This device is a desktop-type synchrotron radiation generator, and the current waveform supplied to the perturbator is a conventional sine half wave.
- the pulse generator for supplying current to the perturbator was modified to generate a sine wave repeatedly instead of a half sine wave. Specifically, the diode used to form the sine half wave was removed to generate a continuous sine wave. Since no forced vibration was used, the peak of the sine wave attenuated with time in the actual excitation current waveform.
- the pulse generator is a known pulse power source including a charging unit and a magnetic compression circuit. The pulse power supply charges a capacitor by a charging unit, and this discharge current is pulse-compressed through a magnetic compression circuit and applied to a load.
- a system similar to FIG. 2 was constructed.
- a 260 mA beam current was supplied from the microtron section.
- the cycle for repeatedly supplying the excitation current and the beam current was 200 Hz.
- the X-ray intensity generated from the target was measured.
- a tungsten (W) wire having a length of 100 ⁇ m was used as the target.
- the intensity of X-rays emitted from the target was measured using a high energy ion chamber (with a build-up cap) as a detector. The distance between the detector and the X-ray source was 1200 mm.
- Example 1 As shown in FIG. 5, an experiment was conducted by injecting an electron beam into the storage ring device so that the peak of the beam current waveform matched each peak of the decaying excitation current waveform of the perturbator.
- the initial charging voltage of the pulse generator for supplying current to the perturbator was + 600V.
- the horizontal axis represents time
- the left vertical axis represents the excitation current
- the right vertical axis represents the beam current.
- the upper graph shows the case where the peak of the beam current waveform is matched with the first peak of the excitation current waveform.
- the interruption and the lower graph show the case where the peak of the beam current waveform is matched with the second and third peaks of the excitation current waveform, respectively.
- Table 1 shows the X-ray intensities observed under the conditions shown in FIG.
- the first wave in Table 1 indicates that the peak of the beam current is aligned with the first peak of the excitation current.
- the second wave and the third wave respectively indicate that the peak of the beam current is matched with the second and third peaks of the excitation current.
- Table 1 shows that even when the same beam current is supplied, the X-ray intensity decreases as the excitation current decreases. That is, the accumulated current value depends on the intensity of the excitation current.
- Table 2 shows the X-ray intensities observed under the conditions shown in FIG.
- the X-ray intensity decreases, which means that the amount of current taken into the orbit is small.
- the timing at which the electron beam is incident on the storage ring is not properly matched with the timing of the perturbator excitation current, the electron capture efficiency is deteriorated.
- the X-ray intensity (2.9 mGy / min) when the phase difference is 180 degrees is the same as the X-ray intensity when no excitation current is passed through the perturbator.
- the beam current is passed (electrons are made incident on the storage ring) for a period in which a plurality of peaks of the continuous sine wave are included in a state in which the excitation current of the continuous sine wave is passed through the perturbator.
- Current can be taken into the orbit. Therefore, the X-ray intensity can be increased.
- the beam current width is large, there is an advantage that it is not necessary to match the timing at which the beam is incident with the timing at which the excitation current is supplied to the perturbator.
- there are also effects such as jitter.
- this embodiment it is not necessary to consider the influence of jitter.
- the upper image in FIG. 9 and the image in FIG. 10 are images when the beam current width is the conventional width (about 150 ns).
- the lower image in FIG. 9 and the image in FIG. 11 are images when the beam current width is doubled (about 300 ns) as compared with the conventional case.
- the upper images in FIGS. 10 and 11 are enlarged images of a part of the right side in the upper and lower images in FIG. 9, respectively. 10 and 11, the lower image is a graph representing the luminance on the horizontal straight line in the upper image.
- the acceleration cavity 206 is provided in the storage ring main body 200 has been described, but the acceleration cavity 206 may be omitted.
- FIG. 4 shows a case where one circuit formed by four FETs 402, 404, 406, and 408 is included, but a plurality of similar circuits may be connected in parallel according to the required amount of current. That is, a circuit similar to that in FIG. 4 may be formed using four FETs separately, and connected in parallel at the four terminals 420, 422, 424, and 426 in FIG. In that case, a control voltage similar to that of the FETs 402, 404, 406, and 408 may be applied to the gate of the FET of the added circuit.
- the perturbator pulse power supply 220 is not limited to the circuit shown in FIG. Any power source may be used as long as it can supply the excitation current to the perturbator with a continuous sine wave.
- the beam current may not include a range in which the value is substantially constant as shown in FIG. If the beam current width (timing window) is a period that includes multiple peaks of the continuous sine wave of the excitation current, only the number of electrons (current value) taken into the orbit will change even if the beam current value changes. It is.
- the amplitude of the excitation current is substantially constant, but if the period is substantially constant, the amplitude may vary with time. Even if the amplitude of the excitation current changes, the number of electrons (current value) taken into the orbit only changes.
- the apparatus for supplying RF to the microtron is not limited to the klystron, and a magnetron may be used. Furthermore, you may produce
- the electron beam is incident on the electron storage ring.
- the present invention is not limited to this.
- the present invention can be applied to a case where a charged particle beam is incident on a storage ring that takes charged particles that cause betatron oscillation into a circular orbit by a perturbation device.
- the present invention it is possible to store a larger current in the storage ring than in the conventional resonance incidence method using a sine half wave, and it is possible to generate an X-ray having a stronger intensity than in the conventional case.
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Abstract
This method makes a charged particle beam (electron beam) incident to a storage ring that circulates, by means of a perturbator, charged particles (electrons) which are incident from the outside. In a state with continuous flow of an excitation current in the perturbator in which the current strength varies in a sine wave, a charged particle beam is made incident to the storage ring for a time two or more times the period of the excitation current. Thus, a larger current than conventional resonance incidence methods that use half sine waves can be stored in the storage ring, and x-rays with greater intensity can be generated.
Description
本発明は、電子等の荷電粒子を周回させて蓄積する蓄積リングに荷電粒子ビームを入射する方法及びそのシステムに関する。
The present invention relates to a method and system for injecting a charged particle beam into a storage ring that circulates and accumulates charged particles such as electrons.
シンクロトロン等の荷電粒子周回装置(以下、蓄積リングともいう)では、軌道上にパータベータ等の摂動装置を用いて摂動を発生させて、荷電粒子周回装置に入射した荷電粒子を安定周回軌道に取り込む。安定周回軌道に取り込んだ後、安定周回軌道に配置した高周波加速空洞を用いて、安定周回軌道を周回する荷電粒子を加速しても良い。
In a charged particle orbiting device such as a synchrotron (hereinafter also referred to as a storage ring), a perturbation is generated on the orbit using a perturbation device such as a perturbator, and charged particles incident on the charged particle orbiting device are taken into a stable orbit. . After being taken into the stable orbit, charged particles that orbit the stable orbit may be accelerated using a high-frequency acceleration cavity disposed in the stable orbit.
例えば、電子蓄積リングを用いた放射光発生装置(X線発生装置)として、みらくる型放射光発生装置が知られている。みらくる型放射光発生装置は、弱収束シンクロトロンを用いた小型の放射光発生装置である。みらくる型放射光発生装置では、マイクロトロンで加速した電子を蓄積リングへ入射し、入射した電子を周回軌道に乗せるために、パータベータを用いている。即ち、パータベータを構成するコイルにサイン半波の電流(以下、励磁電流ともいう)を流してパルス摂動磁場を発生し、入射する電子を周回させる。サイン半波の励磁電流は一定の周期(例えば1ms(周波数1kHz))で繰り返し印加され、励磁電流が印加される毎に入射する電子が周回軌道に取り込まれ、周回する電子数、即ち蓄積される電流は増大する。例えば、図1に示すように、サイン半波である励磁電流の幅が約150nsであり、電子を入射可能なタイミングウインドウ(ビーム電流幅)は、約100nsである。
For example, a Miracle-type synchrotron radiation generator is known as a synchrotron radiation generator (X-ray generator) using an electron storage ring. The Miracle-type synchrotron radiation generator is a compact synchrotron radiation generator using a weakly focused synchrotron. In the Miracle-type synchrotron radiation generator, a perturbator is used to inject electrons accelerated by a microtron into a storage ring and place the incident electrons on a circular orbit. That is, a sine half-wave current (hereinafter also referred to as an excitation current) is passed through a coil constituting the perturbator to generate a pulse perturbation magnetic field, and circulates incident electrons. The excitation current of the sine half wave is repeatedly applied at a constant period (for example, 1 ms (frequency 1 kHz)), and every time the excitation current is applied, incident electrons are taken into the orbit and accumulated, that is, accumulated. The current increases. For example, as shown in FIG. 1, the width of the excitation current that is a sine half wave is about 150 ns, and the timing window (beam current width) in which electrons can be incident is about 100 ns.
蓄積リングへの電子ビームの入射方法としては、共鳴入射法が知られている。共鳴入射法の詳細は、T.Takayama,“RESONANCE INJECTION METHOD FOR THE CMPACT SUPERCONDUCTING SR-RING”,Nuclear Instruments and Methods in Physics Research,B24/25(1987)420-424(文献1)、H.Yamada,“Commissioning of aurora:The smallest synchrotron light source”,J.Vac.Sci.Technol.B8(6),Nov/Dec 1990,pp.1628-1632(文献2)、高山猛,矢野隆,佐々木泰,安光直樹,「小型シンクロトロン放射光源“オーロラ”単体超電動リングの入射系」,住友重機械技報,Vol.39,No.116,August 1991,pp.11-18(文献3)に開示されており、周知であるので、説明を繰返さない。
As a method for injecting an electron beam into the storage ring, a resonance injection method is known. Details of the resonance injection method can be found in T.W. Takayama, “RESONANCE INJECTION METHOD FOR THE CMPACT SUPERCONDUCTING SR-RING”, Nuclear Instruments and Methods in Physics Research, B24 / 24 (198) -4420 (24/24). Yamada, “Commissioning of aurora: The smallest synchrotron light source”, J. Am. Vac. Sci. Technol. B8 (6), Nov / Dec 1990, pp. 1628-1632 (Reference 2), Takeshi Takayama, Takashi Yano, Yasushi Sasaki, Naoki Anmitsu, “Injection system of a small synchrotron radiation source“ Aurora ”single superelectric ring”, Sumitomo Heavy Industries Technical Report, Vol. 39, no. 116, August 1991, pp. 11-18 (Document 3), which is well known and will not be described repeatedly.
共鳴入射法では、パータベータの励磁電流に、上記したようにサイン半波が使用される。これは、連続サイン波としてパータベータに励磁電流を流した場合、励磁電流の負の部分(逆方向の電流)によって、一旦周回軌道に取り込まれた電子が影響を受けるので、安定して電子を周回させることができないと考えられていたからである。
In the resonance injection method, as described above, a sine half wave is used for the excitation current of the perturbator. This is because when the excitation current flows through the perturbator as a continuous sine wave, the electrons once taken into the orbit are affected by the negative part of the excitation current (current in the reverse direction). It was because it was thought that it could not be made.
また、共鳴入射法では、蓄積リングに電子ビームを入射するタイミングを、パータベータに励磁電流を流すタイミングに正確に合せることが必要であり、その調整が難しい問題がある。また、信号のジッタ(時間変動)による影響を受ける問題もある。
Also, in the resonance incidence method, it is necessary to accurately match the timing at which the electron beam is incident on the storage ring with the timing at which the excitation current is passed through the perturbator, which makes it difficult to adjust. There is also a problem of being affected by signal jitter (time fluctuation).
また、発生する放射線量(X線強度)を上げるためには、電子を入射する回数を上げればよいが、電源の容量を増やすことが必要になり、費用が掛かる問題がある。
Also, in order to increase the amount of radiation (X-ray intensity) generated, the number of incident electrons may be increased. However, it is necessary to increase the capacity of the power source, and there is a problem that costs are increased.
従って、本発明は、サイン半波を使用すること無く、ビーム入射のタイミング制御が容易であり、従来よりも大きい電流を蓄積することができる荷電粒子蓄積リングへのビーム入射方法及びそのシステムを提供することを目的とする。
Therefore, the present invention provides a beam injection method and system for a charged particle storage ring that can easily control the timing of beam injection without using a sine half-wave and can store a larger current than conventional ones. The purpose is to do.
本発明に係る荷電粒子蓄積リングへのビーム入射方法は、外部から入射する荷電粒子を摂動装置によって周回させる蓄積リングに荷電粒子ビームを入射する方法であって、摂動装置に、電流強度がサイン波で変化する電流を連続的に流した状態で、蓄積リングに荷電粒子ビームを入射する。
The beam injection method to the charged particle storage ring according to the present invention is a method in which a charged particle beam is incident on a storage ring that circulates charged particles incident from the outside by a perturbation device, and the current intensity is a sine wave in the perturbation device. A charged particle beam is incident on the storage ring in a state in which a current that changes in (1) is continuously supplied.
好ましくは、摂動装置に連続的に電流を流す時間は、サイン波の周期の2倍以上の時間である。
Preferably, the time for continuously passing the current through the perturbation device is a time that is at least twice the period of the sine wave.
より好ましくは、サイン波の周期の2倍以上の時間、荷電粒子蓄積リングに荷電粒子ビームを入射する。
More preferably, the charged particle beam is incident on the charged particle storage ring for a time longer than twice the period of the sine wave.
本発明に係る荷電粒子蓄積システムは、外部から入射する荷電粒子を摂動装置によって周回させる蓄積リングと、摂動装置に電流を供給する電源と、荷電粒子ビーム生成装置とを備え、電源が、摂動装置に、電流強度がサイン波で変化する電流を連続的に流した状態で、荷電粒子ビーム生成装置が、生成した荷電粒子ビームを蓄積リングに入射する。
A charged particle storage system according to the present invention includes a storage ring that circulates charged particles incident from the outside by a perturbation device, a power source that supplies a current to the perturbation device, and a charged particle beam generation device, and the power source includes the perturbation device. In addition, the charged particle beam generating apparatus makes the generated charged particle beam incident on the storage ring in a state where a current whose current intensity changes with a sine wave is continuously supplied.
本発明によれば、摂動装置に連続サイン波の励磁電流を流した状態で、蓄積リングに荷電粒子ビームを入射することによって、従来よりも大きい電流を蓄積リング内に蓄積することができる。したがって、蓄積リングをX線発生装置として使用する場合、従来よりもX線強度を増大することができる。
According to the present invention, a charged particle beam is incident on the storage ring in a state where a continuous sine wave excitation current is passed through the perturbation device, whereby a larger current than in the conventional case can be stored in the storage ring. Therefore, when the storage ring is used as an X-ray generator, the X-ray intensity can be increased as compared with the conventional case.
本発明によれば、従来必要であったサイン半波の励磁電流を生成するための装置が不要になる。また、荷電粒子ビームを入射するタイミングを、励磁電流を流すタイミングに正確に合せる必要が無く、ジッタの影響も受けない。
According to the present invention, a device for generating a sine half-wave excitation current, which was conventionally necessary, is not necessary. In addition, it is not necessary to accurately match the timing at which the charged particle beam is incident with the timing at which the excitation current flows, and it is not affected by jitter.
本発明によれば、連続サイン波である励磁電流の1周期毎(1波長毎)に荷電粒子を取り込むことができるので、ビーム電流幅に含まれるサイン波の山の数に比例して、X線強度を増大させることができる。例えば、励磁電流として1周期300nsの連続サイン波を用い、ビーム電流幅を6μs(励磁電流の周期の20倍)にすれば、X線強度は20倍となる。
According to the present invention, charged particles can be taken in every period (one wavelength) of the exciting current which is a continuous sine wave, and therefore, in proportion to the number of sine wave peaks included in the beam current width, X The line strength can be increased. For example, if a continuous sine wave having a period of 300 ns is used as the excitation current and the beam current width is 6 μs (20 times the period of the excitation current), the X-ray intensity is 20 times.
100 マイクロトロン本体
102 ビーム取出部
104 RFガイド
108 加速空洞
110 エミッタ(電子銃)
120 基準高周波発振器
122 プリアンプ
124 高電圧パルス電源
126 パルスクライストロン
200 蓄積リング本体
202 ビーム入射部
204 パータベータ
206 加速空洞
208 放射光取出部
220 パータベータパルス電源
230 ターゲット
240 放射光
300 トリガパルス発振器
400 制御信号生成部
402、404、406、408 MOS-FET
410 電源
412 共振用キャパシタ
414 ダンピング抵抗
416 インダクタ(パータベータ) DESCRIPTION OFSYMBOLS 100 Microtron main body 102 Beam extraction part 104 RF guide 108 Acceleration cavity 110 Emitter (electron gun)
120 ReferenceHigh Frequency Oscillator 122 Preamplifier 124 High Voltage Pulse Power Supply 126 Pulse Klystron 200 Storage Ring Main Body 202 Beam Incident Part 204 Perverter 206 Acceleration Cavity 208 Radiation Extraction Part 220 Partator Beta Pulse Power Supply 230 Target 240 Radiation Light 300 Trigger Pulse Oscillator 400 Control Signal Generation 402, 404, 406, 408 MOS-FET
410Power supply 412 Resonance capacitor 414 Damping resistor 416 Inductor (partator)
102 ビーム取出部
104 RFガイド
108 加速空洞
110 エミッタ(電子銃)
120 基準高周波発振器
122 プリアンプ
124 高電圧パルス電源
126 パルスクライストロン
200 蓄積リング本体
202 ビーム入射部
204 パータベータ
206 加速空洞
208 放射光取出部
220 パータベータパルス電源
230 ターゲット
240 放射光
300 トリガパルス発振器
400 制御信号生成部
402、404、406、408 MOS-FET
410 電源
412 共振用キャパシタ
414 ダンピング抵抗
416 インダクタ(パータベータ) DESCRIPTION OF
120 Reference
410
以下の実施の形態では、同一の部品には同一の参照番号を付してある。それらの名称及び機能も同一である。従って、それらについての詳細な説明は繰返さない。
In the following embodiments, the same reference numerals are assigned to the same parts. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.
本発明の実施の形態に係る荷電粒子蓄積システムは、電子を蓄積するシステムであり、電子ビーム生成部、弱収束シンクロトロンを用いた蓄積リング部、及び制御部から構成される。電子ビーム生成部には、例えばマイクロトロンを使用することができる。図2を参照して、電子ビーム生成部は、マイクロトロン本体100、ビーム取出部102、RFガイド104、加速空洞108、エミッタ(電子銃)110、基準高周波発振器120、プリアンプ122、高電圧パルス電源124、及びパルスクライストロン126を備えている。蓄積リング部は、蓄積リング本体200、ビーム入射部202、パータベータ204、加速空洞206、放射光取出部208、及びパータベータパルス電源220を備えている。制御部は、荷電粒子蓄積システム各部の動作タイミングを制御するためのパルス信号を生成するトリガパルス発振器300を備えている。なお、マイクロトロン本体100及び蓄積リング本体200には、図2に示した構成要素以外にも、それぞれマイクロトロン及び蓄積リングとして機能するために必要な公知の部品が装備されている。
The charged particle storage system according to the embodiment of the present invention is a system for storing electrons, and includes an electron beam generation unit, a storage ring unit using a weakly focused synchrotron, and a control unit. For example, a microtron can be used for the electron beam generator. Referring to FIG. 2, the electron beam generation unit includes a microtron main body 100, a beam extraction unit 102, an RF guide 104, an acceleration cavity 108, an emitter (electron gun) 110, a reference high-frequency oscillator 120, a preamplifier 122, a high voltage pulse power source. 124 and a pulse klystron 126. The storage ring unit includes a storage ring main body 200, a beam incident unit 202, a perturbator 204, an acceleration cavity 206, a synchrotron radiation extraction unit 208, and a perturbator pulse power source 220. The control unit includes a trigger pulse oscillator 300 that generates a pulse signal for controlling the operation timing of each part of the charged particle accumulation system. In addition to the components shown in FIG. 2, the microtron main body 100 and the storage ring main body 200 are equipped with known components necessary for functioning as a microtron and a storage ring, respectively.
基準高周波発振器120は、所定の振幅及び所定の周波数の基準高周波信号(マイクロ波)を生成して、プリアンプ122に出力する。基準高周波発振器120は、例えば10mWの基準信号を連続的に出力する。プリアンプ122は、基準高周波発振器120から入力される高周波信号を増幅して、パルスクライストロン126に出力する。プリアンプ122は、例えば、最大出力1000Wのクライストロン前段高周波ゲート式増幅器である。プリアンプ122は、トリガパルス発振器300から入力されるパルス信号に応じて所定期間、入力信号を増幅した信号を出力する。例えば、プリアンプ122は、トリガパルス発振器300から出力されるパルス信号を、出力用のゲートパルスとして用いる。高電圧パルス電源124は、パルスクライストロン用モジュレータ電源である。高電圧パルス電源124は、トリガパルス発振器300からのパルス信号を受けて高電圧パルスを、パルスクライストロン126に出力する。パルスクライストロン126は、高電圧パルス電源124からの高電圧パルスによって発生した電子を、プリアンプ122から入力される高周波信号(マイクロ波)によって速度変調して、大電力のマイクロ波を生成する。生成されたマイクロ波は、RFガイド104に出力される。RFガイド104は、マイクロ波をエミッタ(電子銃)110に伝搬する。パルスクライストロンは、当業者には周知であるのでこれ以上の説明は繰返さない。
The reference high frequency oscillator 120 generates a reference high frequency signal (microwave) having a predetermined amplitude and a predetermined frequency and outputs the reference high frequency signal to the preamplifier 122. The reference high-frequency oscillator 120 continuously outputs, for example, a 10 mW reference signal. The preamplifier 122 amplifies the high frequency signal input from the reference high frequency oscillator 120 and outputs it to the pulse klystron 126. The preamplifier 122 is, for example, a klystron front-stage high-frequency gate amplifier with a maximum output of 1000 W. The preamplifier 122 outputs a signal obtained by amplifying the input signal for a predetermined period according to the pulse signal input from the trigger pulse oscillator 300. For example, the preamplifier 122 uses a pulse signal output from the trigger pulse oscillator 300 as an output gate pulse. The high voltage pulse power supply 124 is a modulator power supply for a pulse klystron. The high voltage pulse power supply 124 receives the pulse signal from the trigger pulse oscillator 300 and outputs a high voltage pulse to the pulse klystron 126. The pulse klystron 126 speed-modulates electrons generated by the high voltage pulse from the high voltage pulse power supply 124 with a high frequency signal (microwave) input from the preamplifier 122 to generate a high power microwave. The generated microwave is output to the RF guide 104. The RF guide 104 propagates the microwave to the emitter (electron gun) 110. Since pulse klystrons are well known to those skilled in the art, further description will not be repeated.
RFガイド104を介して伝搬されたマイクロ波によって、加速空洞108に高周波電場が形成される。この状態で、エミッタ(電子銃)110を加熱して電子を放出させると、放出された電子は、高周波電場によって加速される。マイクロトロン本体100の内部には、所定方向に一様な静磁場が形成されているので、この静磁場によって、放出された電子の軌道は円弧状になる。電子は、加速空洞108を繰返し通過して加速されるにつれて、軌道半径が大きくなるので、電子の軌道は、図2に示したように渦巻状の軌道310になる。最後に電子は、ビーム取出部102から、直線状の電子ビーム312として出力される。電子銃は、当業者には周知であるのでこれ以上の説明は繰返さない。
A high frequency electric field is formed in the acceleration cavity 108 by the microwave propagated through the RF guide 104. In this state, when the emitter (electron gun) 110 is heated to emit electrons, the emitted electrons are accelerated by a high-frequency electric field. Since a uniform static magnetic field is formed in a predetermined direction inside the microtron main body 100, the trajectory of emitted electrons becomes an arc shape by the static magnetic field. As the electrons are repeatedly passed through the acceleration cavity 108 and accelerated, the radius of the orbit increases, so that the electron orbit becomes a spiral orbit 310 as shown in FIG. Finally, the electrons are output from the beam extraction unit 102 as a linear electron beam 312. Since electron guns are well known to those skilled in the art, further description will not be repeated.
マイクロトロン本体100から出力された電子ビーム312は、ビーム入射部202から蓄積リング本体200に入射する。蓄積リング本体200の内部には、所定方向に一様な静磁場が形成されているので、電子ビームの軌道は円弧状に曲げられる。円弧状の軌道を通った電子は、パータベータ204に入射する。このとき、パータベータパルス電源220から所定の電流がパータベータ204に供給され、摂動磁場が形成される。電子は、この電磁場によって摂動を受けて軌道が修正され、所定の周回軌道314上を回るようになる。その後、周回する電子は、必要に応じて加速空洞206によって加速される。なお、周回軌道314に乗らなかった電子は、軌道316のように蓄積リング本体200の壁などに衝突して消失する。
The electron beam 312 output from the microtron main body 100 is incident on the storage ring main body 200 from the beam incident portion 202. Since a uniform static magnetic field is formed in a predetermined direction inside the storage ring main body 200, the trajectory of the electron beam is bent in an arc shape. The electrons that have passed through the circular arc trajectory enter the perturbator 204. At this time, a predetermined current is supplied from the perturbator pulse power source 220 to the perturbator 204, and a perturbation magnetic field is formed. The electrons are perturbed by this electromagnetic field, the trajectory is corrected, and the electrons travel on a predetermined orbit 314. Thereafter, the circulating electrons are accelerated by the acceleration cavity 206 as necessary. It should be noted that the electrons that did not get on the circular orbit 314 collide with the wall of the storage ring main body 200 or the like like the orbit 316 and disappear.
このようにして、マイクロトロン部から所定のタイミングで入射される電子を、蓄積リング本体200の内部で周回させることできる。周回する電子が、ターゲット230に入射すると、X線などの放射光240を発生する。発生した放射光240は、放射光取出部208から取り出されて、種々の用途に利用される。
In this way, electrons incident at a predetermined timing from the microtron part can be circulated inside the storage ring main body 200. When the circulating electrons enter the target 230, emitted light 240 such as X-rays is generated. The generated synchrotron radiation 240 is extracted from the synchrotron radiation extraction section 208 and used for various purposes.
図3及び図4を参照して、本実施の形態に係る蓄積リングへのビームの入射方法と、そのためのパータベータパルス電源の詳細について説明する。
With reference to FIG. 3 and FIG. 4, the details of the beam incidence method to the storage ring according to the present embodiment and the perturbator pulse power supply therefor will be described.
従来では、図1に示したサイン半波の電流をパータベータに供給した状態で、サイン半波のビーム電流として、電子を蓄積リングに入射していた。これに対して、本実施の形態に係る電子ビームの入射方法では、図3に示したように、パータベータ204に連続サイン波の励磁電流を供給した状態で、マイクロトロン部から電子ビーム312を所定の時間(ビーム電流幅)蓄積リング本体200に入射する。即ち、従来では、パータベータに一方向(正方向)の電流しか流さなかったが、本実施の形態では、両方向(正負方向)に電流を流す。蓄積リング本体200に入射する電子、即ちビーム電流は、サイン波である励磁電流の1周期よりも長い時間、略一定の値で供給される。これによって、図3のビーム電流のうち符号Aで示した部分の電子が、パータベータ204による摂動を受けて周回軌道314上に取り込まれる。符号Aで示した部分以外のビーム電流(電子)は、周回軌道314に取り込まれずに、壁などに当たって消失する。
Conventionally, electrons are incident on the storage ring as a sine half-wave beam current with the sine half-wave current shown in FIG. 1 supplied to the perturbator. On the other hand, in the electron beam incidence method according to the present embodiment, as shown in FIG. 3, the electron beam 312 is emitted from the microtron unit in a state where a continuous sine wave excitation current is supplied to the perturbator 204. For a period of time (beam current width) enters the storage ring main body 200. That is, conventionally, only a current in one direction (positive direction) flows through the perturbator, but in this embodiment, a current flows in both directions (positive and negative directions). Electrons incident on the storage ring body 200, that is, a beam current, are supplied at a substantially constant value for a time longer than one cycle of the exciting current that is a sine wave. As a result, a part of the beam current indicated by symbol A in the beam current of FIG. 3 is perturbed by the perturbator 204 and taken into the orbit 314. The beam current (electrons) other than the portion indicated by the reference symbol A is not taken into the circular orbit 314 but hits the wall and disappears.
このようにして、1つのサイン半波によって蓄積できる電流の数倍の電流を蓄積リングに取り込むことができる。例えば図3では、3つの山の期間にわたってビーム電流が流れる(電子が供給される)ので、サイン半波を使用する場合の約3倍の電流を蓄積できる。蓄積される電流が大きければ、ターゲットによって放射される放射光(X線)強度が増大する。
In this way, several times the current that can be stored by one sine half wave can be taken into the storage ring. For example, in FIG. 3, since a beam current flows (electrons are supplied) over a period of three peaks, it is possible to accumulate about three times as much current as when using a sine half wave. If the accumulated current is large, the intensity of radiated light (X-ray) emitted by the target increases.
なお、所定の時間連続するサイン波の励磁電流をパータベータに供給し、その間に電子を所定の時間(ビーム電流幅)入射することを、一定の周期で繰返せば、周回する電子数、即ち蓄積される電流は増大する。
If the excitation current of a sine wave that continues for a predetermined time is supplied to the perturbator and the electrons are incident for a predetermined time (beam current width) during that period, the number of circulating electrons, that is, accumulation is repeated. Current is increased.
図3に示した励磁電流は、例えば図4の回路によって実現することができる。図4を参照して、パータベータパルス電源220は、制御信号生成部400、4つのMOS-FET(以下、単にFETと記す)402、404、406、408、直流電源410、共振用キャパシタ412、及びダンピング抵抗414を備えている。図4のインダクタ416は、パータベータ204を形成するコイルを表している。4つのFET402、404、406、408によって形成される回路は、4つの端子420、422、424、426を介して、電源410、共振用キャパシタ412、及びインダクタ416に接続されている。パータベータパルス電源220から、インダクタ416(パータベータ)に、所定の励磁電流を供給する。パータベータ204のインダクタンスは、例えば150nHである。直流電源は、例えばDC300V、50kWを供給する。
The excitation current shown in FIG. 3 can be realized by the circuit of FIG. 4, for example. Referring to FIG. 4, a perturbator pulse power supply 220 includes a control signal generator 400, four MOS-FETs (hereinafter simply referred to as FETs) 402, 404, 406, 408, a DC power supply 410, a resonance capacitor 412, And a damping resistor 414. The inductor 416 in FIG. 4 represents a coil that forms the perturbator 204. The circuit formed by the four FETs 402, 404, 406, and 408 is connected to the power source 410, the resonance capacitor 412, and the inductor 416 via the four terminals 420, 422, 424, and 426. A predetermined excitation current is supplied from the perturbator pulse power supply 220 to the inductor 416 (perturbator). The inductance of the perturbator 204 is, for example, 150 nH. The DC power supply supplies, for example, DC 300 V and 50 kW.
制御信号生成部400は、トリガパルス発振器300から入力されるパルス信号をトリガとして所定の時間、4つのFET402、404、406、408のゲートに所定のタイミングで制御電圧を印加する。制御電圧の一例を、図3に示す。図3では、サイン波の励磁電流と同じ時間軸で、各FETのゲートに印加する制御電圧を示している。制御電圧の周期は、励磁電流の周期と同じである。図3に示すように、FET402及び408にハイレベルの電圧を印加するときには、FET404及び406にはローレベルの電圧を印加する。FET402及び408にローレベルの電圧を印加するときには、FET404及び406にはハイレベルの電圧を印加する。これによって、パータベータ204に両方向の電流を流すことができる。共振用キャパシタ412は、インダクタ416と直列共振を生じるように容量値が設定されている。したがって、図3に示したようなサイン波の電流をパータベータ204に流すことができる。
The control signal generator 400 applies a control voltage to the gates of the four FETs 402, 404, 406, and 408 at a predetermined timing for a predetermined time using the pulse signal input from the trigger pulse oscillator 300 as a trigger. An example of the control voltage is shown in FIG. FIG. 3 shows the control voltage applied to the gate of each FET on the same time axis as the sine wave excitation current. The cycle of the control voltage is the same as the cycle of the excitation current. As shown in FIG. 3, when a high level voltage is applied to the FETs 402 and 408, a low level voltage is applied to the FETs 404 and 406. When a low level voltage is applied to the FETs 402 and 408, a high level voltage is applied to the FETs 404 and 406. As a result, currents in both directions can flow through the perturbator 204. The capacitance of the resonance capacitor 412 is set so as to cause series resonance with the inductor 416. Therefore, a sine wave current as shown in FIG.
以下に、実験結果を示す。実験には、既存の蓄積リング装置「MIRRORCLE-CV4(株式会社光子発生技術研究所製)」を用いた。同装置は、卓上型の放射光発生装置であり、パータベータに供給される電流波形は、従来のサイン半波である。実験では、パータベータに電流を供給するためのパルス発生器を、サイン半波ではなく、繰り返しサイン波を発生するように改造した。具体的には、サイン半波を形成するために使用されていたダイオードを取り除いて、連続サイン波を発生させた。強制振動はさせなかったので、実際の励磁電流波形は、サイン波のピークが時間とともに減衰した。なお、パルス発生器は、充電部と磁気圧縮回路とを備えた公知のパルス電源である。パルス電源は、充電部によってキャパシタを充電し、この放電電流を、磁気圧縮回路を通してパルス圧縮し、負荷に印加する。
The experimental results are shown below. In the experiment, an existing storage ring device “MIRRORCLE-CV4 (manufactured by Photon Generation Technology Laboratory Co., Ltd.)” was used. This device is a desktop-type synchrotron radiation generator, and the current waveform supplied to the perturbator is a conventional sine half wave. In the experiment, the pulse generator for supplying current to the perturbator was modified to generate a sine wave repeatedly instead of a half sine wave. Specifically, the diode used to form the sine half wave was removed to generate a continuous sine wave. Since no forced vibration was used, the peak of the sine wave attenuated with time in the actual excitation current waveform. The pulse generator is a known pulse power source including a charging unit and a magnetic compression circuit. The pulse power supply charges a capacitor by a charging unit, and this discharge current is pulse-compressed through a magnetic compression circuit and applied to a load.
改造した蓄積リング装置「MIRRORCLE-CV4」を用いて、図2と同様のシステムを構成した。マイクロトロン部からは、260mAのビーム電流を供給した。励磁電流及びビーム電流を繰返し供給する周期は200Hzとした。蓄積された電流値を評価するために、ターゲットから発生するX線強度を測定した。ターゲットには、長さ100μmのタングステン(W)のワイヤを用いた。ターゲットから放射されるX線の強度を、検出器として高エネルギー用イオンチャンバー(ビルドアップキャップ有り)を用いて測定した。検出器とX線ソースとの距離は1200mmとした。
Using the modified storage ring device “MIRRORCLE-CV4”, a system similar to FIG. 2 was constructed. A 260 mA beam current was supplied from the microtron section. The cycle for repeatedly supplying the excitation current and the beam current was 200 Hz. In order to evaluate the accumulated current value, the X-ray intensity generated from the target was measured. A tungsten (W) wire having a length of 100 μm was used as the target. The intensity of X-rays emitted from the target was measured using a high energy ion chamber (with a build-up cap) as a detector. The distance between the detector and the X-ray source was 1200 mm.
<実験1>
図5に示すように、ビーム電流波形のピークが、減衰するパータベータの励磁電流波形の各ピークに合うように、電子ビームを蓄積リング装置に入射して実験した。パータベータに電流を供給するパルス発生器の初期充電電圧は+600Vにした。図5において、横軸は時間であり、左側の縦軸は励磁電流を表し、右側の縦軸はビーム電流を表す。上段のグラフは、ビーム電流波形のピークを、励磁電流波形の第1番目のピークに合せた場合を示す。同様に、中断及び下段のグラフはそれぞれ、ビーム電流波形のピークを、励磁電流波形の第2番目及び第3番目のピークに合せた場合を示す。 <Experiment 1>
As shown in FIG. 5, an experiment was conducted by injecting an electron beam into the storage ring device so that the peak of the beam current waveform matched each peak of the decaying excitation current waveform of the perturbator. The initial charging voltage of the pulse generator for supplying current to the perturbator was + 600V. In FIG. 5, the horizontal axis represents time, the left vertical axis represents the excitation current, and the right vertical axis represents the beam current. The upper graph shows the case where the peak of the beam current waveform is matched with the first peak of the excitation current waveform. Similarly, the interruption and the lower graph show the case where the peak of the beam current waveform is matched with the second and third peaks of the excitation current waveform, respectively.
図5に示すように、ビーム電流波形のピークが、減衰するパータベータの励磁電流波形の各ピークに合うように、電子ビームを蓄積リング装置に入射して実験した。パータベータに電流を供給するパルス発生器の初期充電電圧は+600Vにした。図5において、横軸は時間であり、左側の縦軸は励磁電流を表し、右側の縦軸はビーム電流を表す。上段のグラフは、ビーム電流波形のピークを、励磁電流波形の第1番目のピークに合せた場合を示す。同様に、中断及び下段のグラフはそれぞれ、ビーム電流波形のピークを、励磁電流波形の第2番目及び第3番目のピークに合せた場合を示す。 <
As shown in FIG. 5, an experiment was conducted by injecting an electron beam into the storage ring device so that the peak of the beam current waveform matched each peak of the decaying excitation current waveform of the perturbator. The initial charging voltage of the pulse generator for supplying current to the perturbator was + 600V. In FIG. 5, the horizontal axis represents time, the left vertical axis represents the excitation current, and the right vertical axis represents the beam current. The upper graph shows the case where the peak of the beam current waveform is matched with the first peak of the excitation current waveform. Similarly, the interruption and the lower graph show the case where the peak of the beam current waveform is matched with the second and third peaks of the excitation current waveform, respectively.
図5に示した条件で観測されたX線強度を表1に示す。
Table 1 shows the X-ray intensities observed under the conditions shown in FIG.
表1の第1波目は、ビーム電流のピークを励磁電流の第1番目のピークに合せたことを表す。第2波目及び第3波目はそれぞれ、ビーム電流のピークを励磁電流の第2番目及び第3番目のピークに合せたことを表す。表1から、同じビーム電流を供給した場合であっても、励磁電流が減少するにつれて、X線強度も減少することが分かる。即ち、蓄積される電流値は、励磁電流の強度に依存する。
The first wave in Table 1 indicates that the peak of the beam current is aligned with the first peak of the excitation current. The second wave and the third wave respectively indicate that the peak of the beam current is matched with the second and third peaks of the excitation current. Table 1 shows that even when the same beam current is supplied, the X-ray intensity decreases as the excitation current decreases. That is, the accumulated current value depends on the intensity of the excitation current.
<実験2>
図5と同じ励磁電流を加えて、励磁電流波形に対するビーム電流波形の位相を変化させて実験した。具体的には、図6に示すように、ビーム電流波形のピークの位置を、減衰する励磁電流波形の第1番目のピークの位置から変化させて実験した。図6の各軸の意味は、図5と同じである。上段のグラフは、ビーム電流波形のピークを、励磁電流波形の第1番目のピークに合せた場合を示す。中断及び下段のグラフはそれぞれ、ビーム電流波形のピークを、励磁電流波形のピークから90度及び180度遅らせた場合を示す。 <Experiment 2>
Experiments were performed by applying the same excitation current as in FIG. 5 and changing the phase of the beam current waveform with respect to the excitation current waveform. Specifically, as shown in FIG. 6, the experiment was performed by changing the peak position of the beam current waveform from the position of the first peak of the decaying excitation current waveform. The meaning of each axis in FIG. 6 is the same as in FIG. The upper graph shows the case where the peak of the beam current waveform is matched with the first peak of the excitation current waveform. The interruption and lower graphs show the case where the peak of the beam current waveform is delayed by 90 degrees and 180 degrees from the peak of the excitation current waveform, respectively.
図5と同じ励磁電流を加えて、励磁電流波形に対するビーム電流波形の位相を変化させて実験した。具体的には、図6に示すように、ビーム電流波形のピークの位置を、減衰する励磁電流波形の第1番目のピークの位置から変化させて実験した。図6の各軸の意味は、図5と同じである。上段のグラフは、ビーム電流波形のピークを、励磁電流波形の第1番目のピークに合せた場合を示す。中断及び下段のグラフはそれぞれ、ビーム電流波形のピークを、励磁電流波形のピークから90度及び180度遅らせた場合を示す。 <
Experiments were performed by applying the same excitation current as in FIG. 5 and changing the phase of the beam current waveform with respect to the excitation current waveform. Specifically, as shown in FIG. 6, the experiment was performed by changing the peak position of the beam current waveform from the position of the first peak of the decaying excitation current waveform. The meaning of each axis in FIG. 6 is the same as in FIG. The upper graph shows the case where the peak of the beam current waveform is matched with the first peak of the excitation current waveform. The interruption and lower graphs show the case where the peak of the beam current waveform is delayed by 90 degrees and 180 degrees from the peak of the excitation current waveform, respectively.
図6に示した条件で観測されたX線強度を表2に示す。
Table 2 shows the X-ray intensities observed under the conditions shown in FIG.
ビーム電流波形及び励磁電流波形の位相をずらせるとX線強度が減少していることは、周回軌道に取り込まれる電流量が少ないことを表している。このように、ビーム電流にサイン半波を使用する場合には、電子ビームを蓄積リングに入射するタイミングを、パータベータ励磁電流のタイミングにうまく合せないと、電子の取り込み効率が悪くなる。なお、位相差180度の場合のX線強度(2.9mGy/min)は、パータベータに励磁電流を流さなかった場合のX線強度と同じであった。
When the phase of the beam current waveform and the excitation current waveform is shifted, the X-ray intensity decreases, which means that the amount of current taken into the orbit is small. As described above, when a sine half wave is used for the beam current, if the timing at which the electron beam is incident on the storage ring is not properly matched with the timing of the perturbator excitation current, the electron capture efficiency is deteriorated. Note that the X-ray intensity (2.9 mGy / min) when the phase difference is 180 degrees is the same as the X-ray intensity when no excitation current is passed through the perturbator.
<実験3>
パータベータに電流を供給するパルス発生器の初期充電電圧を+650Vにし、図7に示すように、ビーム電流波形のピークを、励磁電流波形の第2番目のピークに合せて実験した。その結果、観測されたX線強度を表3に示す。 <Experiment 3>
The initial charging voltage of the pulse generator that supplies current to the perturbator was set to +650 V, and the peak of the beam current waveform was adjusted to the second peak of the excitation current waveform as shown in FIG. As a result, the observed X-ray intensity is shown in Table 3.
パータベータに電流を供給するパルス発生器の初期充電電圧を+650Vにし、図7に示すように、ビーム電流波形のピークを、励磁電流波形の第2番目のピークに合せて実験した。その結果、観測されたX線強度を表3に示す。 <Experiment 3>
The initial charging voltage of the pulse generator that supplies current to the perturbator was set to +650 V, and the peak of the beam current waveform was adjusted to the second peak of the excitation current waveform as shown in FIG. As a result, the observed X-ray intensity is shown in Table 3.
表1及び表2から、励磁電流の大きさが同じ(1010A)であれば、第2番目のピークを使用しても、同程度の効率で電子を周回軌道に取り込めることが分かる。
From Tables 1 and 2, it can be seen that if the magnitude of the excitation current is the same (1010 A), even if the second peak is used, electrons can be taken into the orbit with the same degree of efficiency.
<実験4>
図8に示すように、ビーム電流幅を広げて、同様に実験を行なった。図8の上段及び下段のグラフはそれぞれ、パータベータへの印加電圧を650V及び600Vに設定した場合を示す。その結果、観測されたX線強度を表4に示す。 <Experiment 4>
As shown in FIG. 8, the experiment was performed in the same manner with the beam current width increased. The upper and lower graphs in FIG. 8 show the cases where the applied voltage to the perturbator is set to 650 V and 600 V, respectively. As a result, the observed X-ray intensity is shown in Table 4.
図8に示すように、ビーム電流幅を広げて、同様に実験を行なった。図8の上段及び下段のグラフはそれぞれ、パータベータへの印加電圧を650V及び600Vに設定した場合を示す。その結果、観測されたX線強度を表4に示す。 <Experiment 4>
As shown in FIG. 8, the experiment was performed in the same manner with the beam current width increased. The upper and lower graphs in FIG. 8 show the cases where the applied voltage to the perturbator is set to 650 V and 600 V, respectively. As a result, the observed X-ray intensity is shown in Table 4.
表1と表4とを比較すると、パータベータへの印加電圧が650Vの場合(励磁電流が第2番目のピークで1010A)、ビーム電流幅を第1番目及び第2番目のピークをカバーするように広げると、X線強度が2倍になることが分かる。パータベータへの印加電圧が600Vの場合には、X線強度は2倍にはならなった。しかし、表4の印加電圧600Vの場合のX線強度20mGy/minは、表1の第1波目及び第2波目のX線強度の和である18.1Gy/min(=11.3+6.8)よりも大きい。これらのことから、励磁電流の第1番目及び第2番目のピークによって、電子を周回軌道に取り込めたことが分かる。
Comparing Table 1 and Table 4, when the applied voltage to the perturbator is 650 V (excitation current is 1010 A at the second peak), the beam current width is to cover the first and second peaks. It can be seen that the X-ray intensity doubles when expanded. When the applied voltage to the perturbator was 600 V, the X-ray intensity doubled. However, the X-ray intensity of 20 mGy / min in the case of the applied voltage of 600 V in Table 4 is the sum of the X-ray intensities of the first wave and the second wave in Table 1, 18.1 Gy / min (= 11.3 + 6. Greater than 8). From these facts, it can be seen that the first and second peaks of the excitation current have taken electrons into the orbit.
このように、パータベータに連続サイン波の励磁電流を流した状態で、連続サイン波の複数の山が含まれる期間、ビーム電流を流す(蓄積リングに電子を入射する)ことによって、従来よりも大きい電流を周回軌道に取り込むことができる。したがって、X線強度を増大させることができる。また、ビーム電流幅が大きいので、ビームを入射するタイミングを、パータベータに励磁電流を流すタイミングに合せることが不要になる利点がある。従来の共鳴入射法では、パータベータに励磁電流(パルス半波)を流すタイミングに合せて、電子ビーム(パルス半波)を蓄積リングに入射することが必要であるが、これは容易ではない。また、実際にはジッタなどの影響もある。これに対して、本実施の形態では、ジッタの影響を考慮する必要もない。
As described above, the beam current is passed (electrons are made incident on the storage ring) for a period in which a plurality of peaks of the continuous sine wave are included in a state in which the excitation current of the continuous sine wave is passed through the perturbator. Current can be taken into the orbit. Therefore, the X-ray intensity can be increased. Further, since the beam current width is large, there is an advantage that it is not necessary to match the timing at which the beam is incident with the timing at which the excitation current is supplied to the perturbator. In the conventional resonance injection method, it is necessary to inject an electron beam (pulse half wave) into the storage ring in accordance with the timing when an excitation current (pulse half wave) flows through the perturbator, but this is not easy. In actuality, there are also effects such as jitter. On the other hand, in this embodiment, it is not necessary to consider the influence of jitter.
図9~図11は、パータベータへの印加電圧を650Vに設定し、ビーム電流幅を変化させて、X線イメージングを行なった結果を示す。イメージングの対象物には、市販の「テストチャートType14(極光株式会社製)」を用いた。これは、X線イメージングの解像度を評価するために使用され、厚さ30μmの鉛シートに幅の異なる複数の溝が刻まれた装置である。
9 to 11 show the results of X-ray imaging performed by setting the voltage applied to the perturbator to 650 V and changing the beam current width. A commercially available “Test Chart Type 14 (manufactured by Genko Inc.)” was used as an object to be imaged. This device is used to evaluate the resolution of X-ray imaging, and is a device in which a plurality of grooves having different widths are engraved in a lead sheet having a thickness of 30 μm.
図9の上段の画像、及び図10の画像は、ビーム電流幅を従来の幅(約150ns)にした場合の画像である。図9の下段の画像、及び図11の画像は、ビーム電流幅を従来の2倍(約300ns)にした場合の画像である。図10及び図11の上段の画像はそれぞれ、図9の上段及び下段の画像における右側の一部を拡大した画像である。図10及び図11において、下段の画像は、上段の画像における横方向の直線上の輝度を表すグラフである。
The upper image in FIG. 9 and the image in FIG. 10 are images when the beam current width is the conventional width (about 150 ns). The lower image in FIG. 9 and the image in FIG. 11 are images when the beam current width is doubled (about 300 ns) as compared with the conventional case. The upper images in FIGS. 10 and 11 are enlarged images of a part of the right side in the upper and lower images in FIG. 9, respectively. 10 and 11, the lower image is a graph representing the luminance on the horizontal straight line in the upper image.
図9~図11から分かるように、ビーム電流幅を広くしても、従来と同等の品質のX線画像が得られることが分かる(20本/mmのラインが識別できているので、解像度は1mm/40=25μmである)。即ち、パータベータ励磁電流として連続サイン波を使用しても、周回軌道に一旦取り込まれた電子にほとんど影響しないことが分かった。また、周回軌道から外れたエスケープ電子によるバックグラウンドX線の影響はほとんど無いことが分かった。
As can be seen from FIGS. 9 to 11, it can be seen that even if the beam current width is widened, an X-ray image of the same quality as the conventional one can be obtained (since 20 lines / mm can be identified, the resolution is 1 mm / 40 = 25 μm). That is, it has been found that even if a continuous sine wave is used as the perturbator excitation current, the electrons once taken into the orbit are hardly affected. It was also found that there was almost no influence of background X-rays due to escaped electrons deviating from the orbit.
上記では、蓄積リング本体200内に加速空洞206を備える場合を説明したが、加速空洞206は無くてもよい。
In the above, the case where the acceleration cavity 206 is provided in the storage ring main body 200 has been described, but the acceleration cavity 206 may be omitted.
また、図4は、4つのFET402、404、406、408が形成する回路を1つ含む場合を示したが、必要な電流量に応じて、同様の回路を複数並列に接続してもよい。即ち、別途に4つのFETを用いて図4と同様の回路を形成し、図4の4つの端子420、422、424、426で並列に接続すればよい。その場合、追加した回路のFETのゲートには、FET402、404、406、408と同様の制御電圧を印加すればよい。
FIG. 4 shows a case where one circuit formed by four FETs 402, 404, 406, and 408 is included, but a plurality of similar circuits may be connected in parallel according to the required amount of current. That is, a circuit similar to that in FIG. 4 may be formed using four FETs separately, and connected in parallel at the four terminals 420, 422, 424, and 426 in FIG. In that case, a control voltage similar to that of the FETs 402, 404, 406, and 408 may be applied to the gate of the FET of the added circuit.
また、パータベータパルス電源220は図4に示した回路に限定されない。連続サイン波で励磁電流をパータベータに供給することができる電源であればよい。
Further, the perturbator pulse power supply 220 is not limited to the circuit shown in FIG. Any power source may be used as long as it can supply the excitation current to the perturbator with a continuous sine wave.
また、ビーム電流は、図3に示したように値がほぼ一定になる範囲を含んでいなくてもよい。ビーム電流幅(タイミングウインドウ)が、励磁電流の連続サイン波の複数の山を含む期間であれば、ビーム電流値が変化しても、周回軌道に取り込まれる電子数(電流値)が変化するだけである。
Further, the beam current may not include a range in which the value is substantially constant as shown in FIG. If the beam current width (timing window) is a period that includes multiple peaks of the continuous sine wave of the excitation current, only the number of electrons (current value) taken into the orbit will change even if the beam current value changes. It is.
また、励磁電流の振幅は略一定であることが望ましいが、周期が略一定であれば、振幅が時間的に変動してもよい。励磁電流の振幅が変化しても、周回軌道に取り込まれる電子数(電流値)が変化するだけである。
In addition, it is desirable that the amplitude of the excitation current is substantially constant, but if the period is substantially constant, the amplitude may vary with time. Even if the amplitude of the excitation current changes, the number of electrons (current value) taken into the orbit only changes.
また、マイクロトロンにRFを供給する装置は、クライストロンに限定されず、マグネトロンを用いてもよい。さらに、マイクロトロン以外の装置を用いて電子ビームを生成してもよい。
Further, the apparatus for supplying RF to the microtron is not limited to the klystron, and a magnetron may be used. Furthermore, you may produce | generate an electron beam using apparatuses other than a microtron.
また、上記では、電子蓄積リングに電子ビームを入射する場合について説明したが、これに限定されない。本発明は、ベータトロン振動を起こす荷電粒子を摂動装置によって周回軌道に取り込む蓄積リングに、荷電粒子ビームを入射する場合に適用できる。
In the above description, the electron beam is incident on the electron storage ring. However, the present invention is not limited to this. The present invention can be applied to a case where a charged particle beam is incident on a storage ring that takes charged particles that cause betatron oscillation into a circular orbit by a perturbation device.
以上、実施の形態を説明することにより本発明を説明したが、上記した実施の形態は例示であって、本発明は上記した実施の形態に限定されるものではなく、種々変更して実施することができる。
The present invention has been described above by describing the embodiment. However, the above-described embodiment is an exemplification, and the present invention is not limited to the above-described embodiment, and is implemented with various modifications. be able to.
本発明によれば、サイン半波を使用する従来の共鳴入射法よりも大きい電流を蓄積リング内に蓄積することができ、従来よりも強度の強いX線を発生することができる。
According to the present invention, it is possible to store a larger current in the storage ring than in the conventional resonance incidence method using a sine half wave, and it is possible to generate an X-ray having a stronger intensity than in the conventional case.
Claims (4)
- 外部から入射する荷電粒子を摂動装置によって周回させる蓄積リングに荷電粒子ビームを入射する方法であって、
前記摂動装置に、電流強度がサイン波で変化する電流を連続的に流した状態で、
前記蓄積リングに前記荷電粒子ビームを入射する、荷電粒子蓄積リングへのビーム入射方法。 A charged particle beam is incident on a storage ring that circulates charged particles incident from outside by a perturbation device.
In the state in which the current whose current intensity changes with a sine wave continuously flows through the perturbation device,
A method of injecting a beam into a charged particle storage ring, wherein the charged particle beam is incident on the storage ring. - 前記摂動装置に連続的に電流を流す時間は、前記サイン波の周期の2倍以上の時間である、請求項1に記載の荷電粒子蓄積リングへのビーム入射方法。 2. The method for injecting a beam into a charged particle storage ring according to claim 1, wherein the time for continuously passing a current through the perturbation device is a time that is at least twice the period of the sine wave.
- 前記サイン波の周期の2倍以上の時間、前記荷電粒子蓄積リングに前記荷電粒子ビームを入射する、請求項2に記載の荷電粒子蓄積リングへのビーム入射方法。 3. The method for injecting a beam into a charged particle storage ring according to claim 2, wherein the charged particle beam is incident on the charged particle storage ring for a time that is at least twice the period of the sine wave.
- 外部から入射する荷電粒子を摂動装置によって周回させる蓄積リングと、
前記摂動装置に電流を供給する電源と、
荷電粒子ビーム生成装置とを備え、
前記電源が、前記摂動装置に、電流強度がサイン波で変化する電流を連続的に流した状態で、前記荷電粒子ビーム生成装置が、生成した荷電粒子ビームを前記蓄積リングに入射する、荷電粒子蓄積システム。 A storage ring that circulates charged particles incident from outside by a perturbation device;
A power supply for supplying current to the perturbation device;
A charged particle beam generator,
A charged particle in which the charged particle beam generator impinges the generated charged particle beam on the storage ring in a state in which the power source continuously supplies a current whose sine wave changes in current intensity to the perturbation device. Accumulation system.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
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JP2012548555A JP5718940B2 (en) | 2010-12-13 | 2010-12-13 | Beam injection method and system for charged particle storage ring |
PCT/JP2010/072367 WO2012081070A1 (en) | 2010-12-13 | 2010-12-13 | Method for making beam incident to charged particle storage ring and system therefor |
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Cited By (2)
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WO2015068232A1 (en) * | 2013-11-07 | 2015-05-14 | 株式会社光子発生技術研究所 | Method for beam entrance to charged particle storage ring and system thereof |
CN112616237A (en) * | 2020-12-07 | 2021-04-06 | 中国科学院近代物理研究所 | Method, system and readable medium for generating quasi-sine wave pulse electron beam |
Citations (3)
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JPH08276024A (en) * | 1995-04-07 | 1996-10-22 | Mitsubishi Electric Corp | Timing controller for particle accelerator and timing control thereof |
JP2000164400A (en) * | 1998-11-27 | 2000-06-16 | Sumitomo Heavy Ind Ltd | Beam incident method to storage ring and its device |
WO2007119538A1 (en) * | 2006-03-27 | 2007-10-25 | Photon Production Laboratory, Ltd | Perturbation device for charged particle circulation system |
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2010
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Patent Citations (3)
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JPH08276024A (en) * | 1995-04-07 | 1996-10-22 | Mitsubishi Electric Corp | Timing controller for particle accelerator and timing control thereof |
JP2000164400A (en) * | 1998-11-27 | 2000-06-16 | Sumitomo Heavy Ind Ltd | Beam incident method to storage ring and its device |
WO2007119538A1 (en) * | 2006-03-27 | 2007-10-25 | Photon Production Laboratory, Ltd | Perturbation device for charged particle circulation system |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2015068232A1 (en) * | 2013-11-07 | 2015-05-14 | 株式会社光子発生技術研究所 | Method for beam entrance to charged particle storage ring and system thereof |
US9655226B2 (en) | 2013-11-07 | 2017-05-16 | Photon Production Laboratory, Ltd. | Method and system of beam injection to charged particle storage ring |
CN112616237A (en) * | 2020-12-07 | 2021-04-06 | 中国科学院近代物理研究所 | Method, system and readable medium for generating quasi-sine wave pulse electron beam |
CN112616237B (en) * | 2020-12-07 | 2023-08-11 | 中国科学院近代物理研究所 | Method, system and readable medium for generating quasi-sine wave pulse electron beam |
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JP5718940B2 (en) | 2015-05-13 |
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