在实现高频高压型电子辐照加速器控制系统的分布式控制(Distributed Control System,DCS)的基础上,设计了一个以可编程逻辑控制器(Programmable Logic Controller,PLC)为控制核心,以小脑模型神经网络与PID(Cerebellar Model Articulatio...在实现高频高压型电子辐照加速器控制系统的分布式控制(Distributed Control System,DCS)的基础上,设计了一个以可编程逻辑控制器(Programmable Logic Controller,PLC)为控制核心,以小脑模型神经网络与PID(Cerebellar Model Articulation Controller and Proportional-Integral-Derivative,CMAC-PID)为主要控制算法的束流路径自动校正系统。实验表明:CMAC-PID控制器的调节速率和稳定度相比常规PID控制器均有较大提升,保证加速器在束流路径发生偏转时能快速稳定地将束流自动校正到芯管中间位置。展开更多
The method of energy dispersion in magnetic field is used to analyze the energy spread of the triple-pulse electron beam generated by the Dragon-II linear induction accelerator.A sector magnet is applied for energy an...The method of energy dispersion in magnetic field is used to analyze the energy spread of the triple-pulse electron beam generated by the Dragon-II linear induction accelerator.A sector magnet is applied for energy analysis of the electron beam,with a bending radius of 300 mm and a deflection angle of 90°.For each pulse,the time-resolved and integral images of the electron position at the output port of beam-bending line are recorded by a streak camera and a CCD camera,respectively.Experimental results demonstrate an energy spread of less than ±2.0%for the electron pulses.The cavity voltage waveforms obtained by different detectors are also analyzed for comparison.展开更多
The elliptical reflection zone plate is a kind of optical element in soft x-ray and x-ray ranges and has focusing and dispersion properties. Compared with a transmission zone plate, the required dispersion ordei, can ...The elliptical reflection zone plate is a kind of optical element in soft x-ray and x-ray ranges and has focusing and dispersion properties. Compared with a transmission zone plate, the required dispersion ordei, can be easily separated from zeroth order diffraction. It is fabricated on a bulk substrate and does not have much difficulty in the fabrication process. We design a 1000-zone off-axis elliptical reflection zone plate for the rnonochromatization of the ultrafast betatron radiation at the low energy band, at the designed wavelength of 2.478 nm （500eV） which is an important spectral part of the betatron radiation, with high spatial resolution, high spectral resolution. Moreover, we simulate the designed reflection zone plate properties. The simulation results show that the spatial resolutions in the spatial direction and the spectral direction are 6.4μm and 7.3μm （full width half maximum）, respectively,, and the spectral resolution reaches up to 496 for the well aligned point source system, which is in good agreement with the theoretical predictions. In addition, we discuss some factors influencing the spectral and spatial resolution, such as the zone number, zone area and the incidence wavelength. The elliptical reflection zone plate also has potential applications in investigating x-ray fluorescence spectra and other fields.展开更多
第一轮通知由中国脉冲功率技术及应用学会主办,中国加速器学会协办,中国工程物理研究院流体物理研究所承办的＂第三届国际感应加速器专题研讨会——The Third International Workshop on Recent Progress in Inductio Accelerators,201...第一轮通知由中国脉冲功率技术及应用学会主办,中国加速器学会协办,中国工程物理研究院流体物理研究所承办的＂第三届国际感应加速器专题研讨会——The Third International Workshop on Recent Progress in Inductio Accelerators,2011＂（RPIA’11）将于2011年10月18～21日在四川省都江堰市举行。热忱欢迎国内外同行及相关领域研究人员参加会议。展开更多
In this paper, a new mechanism of electromagnetic instability, the induced ion-channel instability, is stud- ied. It is based on the transverse driven betatron oscillation of relativistic electron beam induced by an a...In this paper, a new mechanism of electromagnetic instability, the induced ion-channel instability, is stud- ied. It is based on the transverse driven betatron oscillation of relativistic electron beam induced by an additional magnetic undulator with a period close to the betatron wavelength in an ion channel. As its amplitude is sensitive to the electron beam energy, the driven betatron oscillation may determine electron beam grouping in the ponderomotive potential by selecting the undulator strength and period, and it provides a new mechanism of electron bunching, re- sulting in electromagnetic instability. Under proper condition, a new free-electron laser based on this mechanism may be realized.展开更多
文摘在实现高频高压型电子辐照加速器控制系统的分布式控制(Distributed Control System,DCS)的基础上,设计了一个以可编程逻辑控制器(Programmable Logic Controller,PLC)为控制核心,以小脑模型神经网络与PID(Cerebellar Model Articulation Controller and Proportional-Integral-Derivative,CMAC-PID)为主要控制算法的束流路径自动校正系统。实验表明:CMAC-PID控制器的调节速率和稳定度相比常规PID控制器均有较大提升,保证加速器在束流路径发生偏转时能快速稳定地将束流自动校正到芯管中间位置。
文摘The method of energy dispersion in magnetic field is used to analyze the energy spread of the triple-pulse electron beam generated by the Dragon-II linear induction accelerator.A sector magnet is applied for energy analysis of the electron beam,with a bending radius of 300 mm and a deflection angle of 90°.For each pulse,the time-resolved and integral images of the electron position at the output port of beam-bending line are recorded by a streak camera and a CCD camera,respectively.Experimental results demonstrate an energy spread of less than ±2.0%for the electron pulses.The cavity voltage waveforms obtained by different detectors are also analyzed for comparison.
基金Supported by the National Natural Science Foundation of China under Grant No 1137516, and the Science Foundation of China Academy of Engineering Physics under Grant Nos 2009A0102003 and 2011B0102021.
文摘The elliptical reflection zone plate is a kind of optical element in soft x-ray and x-ray ranges and has focusing and dispersion properties. Compared with a transmission zone plate, the required dispersion ordei, can be easily separated from zeroth order diffraction. It is fabricated on a bulk substrate and does not have much difficulty in the fabrication process. We design a 1000-zone off-axis elliptical reflection zone plate for the rnonochromatization of the ultrafast betatron radiation at the low energy band, at the designed wavelength of 2.478 nm （500eV） which is an important spectral part of the betatron radiation, with high spatial resolution, high spectral resolution. Moreover, we simulate the designed reflection zone plate properties. The simulation results show that the spatial resolutions in the spatial direction and the spectral direction are 6.4μm and 7.3μm （full width half maximum）, respectively,, and the spectral resolution reaches up to 496 for the well aligned point source system, which is in good agreement with the theoretical predictions. In addition, we discuss some factors influencing the spectral and spatial resolution, such as the zone number, zone area and the incidence wavelength. The elliptical reflection zone plate also has potential applications in investigating x-ray fluorescence spectra and other fields.
文摘第一轮通知由中国脉冲功率技术及应用学会主办,中国加速器学会协办,中国工程物理研究院流体物理研究所承办的＂第三届国际感应加速器专题研讨会——The Third International Workshop on Recent Progress in Inductio Accelerators,2011＂（RPIA’11）将于2011年10月18～21日在四川省都江堰市举行。热忱欢迎国内外同行及相关领域研究人员参加会议。
基金Partially supported by the Major State Basic Research Development Programme of China under Grant No.2002CB713600,the Shanghai Science and Technology Council under Grant No.02QF14059and the Exploration Project of Knowledge Innovation Program of CAS.
文摘In this paper, a new mechanism of electromagnetic instability, the induced ion-channel instability, is stud- ied. It is based on the transverse driven betatron oscillation of relativistic electron beam induced by an additional magnetic undulator with a period close to the betatron wavelength in an ion channel. As its amplitude is sensitive to the electron beam energy, the driven betatron oscillation may determine electron beam grouping in the ponderomotive potential by selecting the undulator strength and period, and it provides a new mechanism of electron bunching, re- sulting in electromagnetic instability. Under proper condition, a new free-electron laser based on this mechanism may be realized.
