期刊文献+
共找到25篇文章
< 1 2 >
每页显示 20 50 100
Electron beam modeling and analyses of the electric field distribution and space charge effect 被引量:1
1
作者 Yueling Jiang Quanlin Dong 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第5期288-293,共6页
In electron beam technology, one of the critical focuses of research and development efforts is on improving the measurement of electron beam parameters. The parameters are closely related to the generation, emission,... In electron beam technology, one of the critical focuses of research and development efforts is on improving the measurement of electron beam parameters. The parameters are closely related to the generation, emission, operation environment, and role of the electron beam and the corresponding medium. In this study, a field calculation method is proposed, and the electric field intensity distribution on the electron beam’s cross-section is analyzed. The characteristics of beam diffusion caused by the space charge effect are investigated in simulation, and the obtained data are compared with the experiment. The simulation demonstrated that the cross-sectional electric field distribution is primarily affected by the electron beam current, current density distribution, and electron beam propagation speed. 展开更多
关键词 electron beam electric field distribution space charge effect
下载PDF
Quantitative evaluation of space charge effects of laser-cooled three-dimensional ion system on a secular motion period scale
2
作者 Li-Jun Du Hong-Fang Song +4 位作者 Shao-Long Chen Yao Huang Xin Tong Hua Guan Ke-Lin Gao 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第4期292-298,共7页
In this paper,we introduce a method of quantitatively evaluating and controlling the space charge effect of a lasercooled three-dimensional(3 D) ion system in a linear Paul trap.The relationship among cooling effici... In this paper,we introduce a method of quantitatively evaluating and controlling the space charge effect of a lasercooled three-dimensional(3 D) ion system in a linear Paul trap.The relationship among cooling efficiency,ion quantity,and trapping strength is analyzed quantitatively,and the dynamic space distribution and temporal evolution of the 3 D ion system on a secular motion period time scale in the cooling process are obtained.The ion number influences the eigen-micromotion feature of the ion system.When trapping parameter q is ~ 0.3,relatively ideal cooling efficiency and equilibrium temperature can be obtained.The decrease of axial electrostatic potential is helpful in reducing the micromotion heating effect and the degradation in the total energy.Within a single secular motion period under different cooling conditions,ions transform from the cloud state(each ion disperses throughout the envelope of the ion system) to the liquid state(each ion is concentrated at a specific location in the ion system) and then to the crystal state(each ion is subjected to a fixed motion track).These results are conducive to long-term storage and precise control,motion effect suppression,high-efficiency cooling,and increasing the precision of spectroscopy for a 3 D ion system. 展开更多
关键词 space charge effects cooling dynamics ion trajectory ion energy
下载PDF
Space Charge Effects in CSL Gauge——with previously assumed charge distribution
3
作者 T.Kanaji T.Urano S.Hongo 《真空科学与技术学报》 EI CAS CSCD 1992年第Z1期83-86,共4页
The "cascade static lens (CSL) gauge" has a high sensitivity(S) because the emitted electrons repeat the go and back oscillation before they are received by the electrodes. (S=18.6 Pa<sup>-1</su... The "cascade static lens (CSL) gauge" has a high sensitivity(S) because the emitted electrons repeat the go and back oscillation before they are received by the electrodes. (S=18.6 Pa<sup>-1</sup> (2480 Torr<sup>-1</sup> in a 展开更多
关键词 CSL with previously assumed charge distribution space charge effects in CSL Gauge
下载PDF
Space Charges Effect of Static Induction Transistor 被引量:1
4
作者 陈金伙 刘肃 +2 位作者 王永顺 李思渊 张福甲 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第3期423-428,共6页
The space charge effect (SCE) of static induction transistor (SIT) that occurs in high current region is systematically studied.The I V equations are deduced and well agree with experimental results.Two kinds of ... The space charge effect (SCE) of static induction transistor (SIT) that occurs in high current region is systematically studied.The I V equations are deduced and well agree with experimental results.Two kinds of barriers are presented in SIT,corresponding to channel voltage barrier control (CVBC) mechanism and space charge limited control (SCLC) mechanism respectively.With the increase of drain voltage,the gradual transferring of operational mechanism from CVBC to SCLC is demonstrated.It points out that CVBC mechanism and its contest relationship with space charge barrier makes the SIT distinctly differentiated from JFET and triode devices,etc.The contest relationship of the two potential barriers also results in three different working regions,which are distinctly marked and analyzed.Furthermore,the extreme importance of grid voltage on SCE is illustrated. 展开更多
关键词 static induction transistor space charge effect space charge potential barrier channel barrier space charge limited control channel voltage barrier control
下载PDF
Study on time-dependent lattice to alleviate space charge effects in CSNS/RCS
5
作者 X.Y.Zhang L.H.Zhang J.Y.Tang 《Radiation Detection Technology and Methods》 CSCD 2019年第1期50-60,共11页
Purpose Tune shift and spread due to the space charge effects and collective instabilities in intense proton synchrotrons,such as the CSNS/RCS,a rapid cycling synchrotron at China Spallation Neutron Source,are the mai... Purpose Tune shift and spread due to the space charge effects and collective instabilities in intense proton synchrotrons,such as the CSNS/RCS,a rapid cycling synchrotron at China Spallation Neutron Source,are the main causes of beam loss.Tune shift/spread is large when the beam kinetic energy is low and will cause particles to cross dangerous resonances,while they will gradually decay with the increase of kinetic energy.Methods An efficient way,which was verified in operational accelerators,is to tune the working point during different acceleration periods:injection,acceleration and extraction.With the newly added function of time-dependent lattice in the ORBIT code,one can simulate the physical performance with different tune patterns to find the best way to reduce beam loss.Results The method to tune the working point by time-dependent lattice to weaken the crossing of dangerous resonances has been exploited,and implemented in the ORBIT code.It is the first of such try to apply the method in CSNS/RCS.Conclusions The results presented in this paper show that the time-dependent lattice method does help reduce beam loss in the injection and early acceleration. 展开更多
关键词 space charge effects Tune shift ORBIT code Time-dependent lattice Nonlinear magnets Resonance Introduction
原文传递
Design of Electrostatic Focusing for Space Electron Beam Welding Gun 被引量:2
6
作者 李春旭 何成旦 +1 位作者 许启晋 蒋彩云 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2005年第3期256-262,共7页
The developmental situation of space welding technology at home and abroad is introduced. Then it is put forward that the designing scheme and the computer aided design (CAD) method of main single lens of the domest... The developmental situation of space welding technology at home and abroad is introduced. Then it is put forward that the designing scheme and the computer aided design (CAD) method of main single lens of the domestic space electron beam gun with equal-diameter three-cylinder simple lens, and the flowing-pipe way of calculating the space charge density of the main lens area ,in the electron gun is analyzed. The parameters calculation of the focusing system is completed through Language C utilizing computer programming and a satisfying result is gotten. The result shows that the calculation and design method are correct : the dispersed focusing current of electron beam is less, the beam section is less in the deflected magnetic field, the minimal radius of beam spot on the workpiece is about 0.65615mm, and all these can meet the requirements of the space welding and cutting. 展开更多
关键词 space welding three-cylinder single lens CAD space charge effect
下载PDF
Effects of Thickness on the Electrical Conductivity of Sputtered YSZ Film with Nanocrystalline Columnar Microstructure 被引量:1
7
作者 YANG Qingqing MENG Bin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第6期1344-1349,共6页
In order to investigate the effect of the thickness on the electrical conductivity of yttriastabilized zirconia(YSZ) film, the nanocrystalline columnar-structured YSZ film with thickness of 0.67-2.52 μm was prepared ... In order to investigate the effect of the thickness on the electrical conductivity of yttriastabilized zirconia(YSZ) film, the nanocrystalline columnar-structured YSZ film with thickness of 0.67-2.52 μm was prepared by magnetron sputtering through controlling the deposition time. All the sputtered films with different thicknesses consist of the main phase of cubic YSZ as well as a small amount of monoclinic YSZ. The thicker films exhibit a typical columnar grain structure based on the fractured cross-sectional SEM observations. The average diameters of columnar grains increase from about 40 nm to 100 nm with the film thickness from 0.67 μm to 2.52 μm according to TEM analysis. The thinnest YSZ film with 0.67 μm thickness shows the highest apparent electrical conductivity in the four films in 400-800 ℃ due to the contribution from the highly conductive film/substrate interfacial region. On the other hand, the real electrical conductivities of YSZ films increase with film thickness from 0.67 μm to 2.52 μm after eliminating the contribution of the film/substrate interface. The increasing film thickness leads to the grain growth as well as the decrement in the volumetric fraction of the resistive columnar grain boundary and a consequent higher real electrical conductivity. 展开更多
关键词 YSZ film columnar microstructure magnetron sputtering interface effect space charge effect
下载PDF
Analytical treatment of the nonlinear electron cloud effect and the combined effects with beam-beam and space charge nonlinear forces in storage rings
8
作者 高杰 《Chinese Physics C》 SCIE CAS CSCD 2009年第2期135-144,共10页
In this paper we treat first some nonlinear beam dynamics problems in storage rings, such as beam dynamic apertures due to magnetic multipoles, wiggles, beam-beam effects, nonlinear space charge effect, and then nonli... In this paper we treat first some nonlinear beam dynamics problems in storage rings, such as beam dynamic apertures due to magnetic multipoles, wiggles, beam-beam effects, nonlinear space charge effect, and then nonlinear electron cloud effect combined with beam-beam and space charge effects, analytically. This analytical treatment is applied to BEPC II. The corresponding analytical expressions developed in this paper are useful both in understanding the physics behind these problems and also in making practical quick hand estimations. 展开更多
关键词 electron cloud effect beam-beam effect space charge effect storage ring BEPC II
原文传递
Quadrupole-Linear Ion Trap Tandem Mass Spectrometry System for Clinical Biomarker Analysis 被引量:5
9
作者 Xiang Fang Jie Xie +8 位作者 Shiying Chu You Jiang Yuting An Chang Li Xiaoyun Gong Rui Zhai Zejian Huang Chunling Qiu Xinhua Dai 《Engineering》 SCIE EI CAS 2022年第9期56-64,共9页
The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built i... The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built in our laboratory.Target precursor ions were first selected in the quadrupole,and then injected,trapped,and fragmented simultaneously in the linear ion trap(LIT)to reduce the space charge effect,enrich the target product ions,and promote sensitivity.The targeted analytes were measured with selected reaction monitoring using a positive scan mode with electrospray ionization(ESI).Ions with a mass-to-charge ratio(m/z)ranging from 195 to 2022 were demonstrated.When scanning at 1218amu.s^(-1),unit resolution and an accuracy of higher than m/z 0.28 was obtained for m/z up to 2000.The dimensionless Mathieu parameter(q)value used in this study was 0.40 for collision-induced dissociation(CID),which was activated by resonance excitation.And an overall CID efficiency of 64%was achieved(activation time,50 ms).Guanidinoacetic acid(GAA)and creatine(CRE)were used as model compounds for small molecule clinical biomarkers.The limits of quantification were 1.0 and 0.2 nmol.L^(-1)for GAA and CRE,respectively.A total of 77 actual samples were successfully analyzed by the home-built ESI-Q-LIT tandem mass spectrometry system.The developed method can reduce matrix interference,minimize space charge effects,and avoid the chromatographic separation of complex samples to simplify the pretreatment process.This novel Q-LIT system is expected to be a good candidate for the determination of biomarkers in clinical diagnosis and therapeutics. 展开更多
关键词 Linear ion trap QUADRUPOLE space charge effect Collision-induced dissociation BIOMARKER
下载PDF
Physical design and cooling test of C-band standing wave accelerating tube 被引量:2
10
作者 柏伟 许州 +1 位作者 金晓 黎明 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第2期319-323,共5页
The physical design and cooling test of a C-band 2MeV standing wave (SW) accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section ... The physical design and cooling test of a C-band 2MeV standing wave (SW) accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section with a total length of about 163mm, excited with 1MW magnetron. Dynamic simulation presents that about 150mA beam pulse current and 30% capture efficiency can be achieved. By means of nonlinear Gauss fit on electron transverse distribution, the diameter of beam spot FWHM (full width at half maximum of density distribution) is about 0.55mm. Cooling test results of the accelerating tube show that frequencies of cavities are tuned to 5527MHz and the field distribution of bunching section is about 3:9:10. 展开更多
关键词 C-BAND standing wave accelerating tube space charge effect
下载PDF
An emittance measurement device for a space-charge dominated electron beam
11
作者 王文静 黄森林 +2 位作者 全胜文 林林 刘克新 《Chinese Physics C》 SCIE CAS CSCD 2012年第9期867-870,共4页
Beam emittance is one of the most important parameters for electron sources. To investigate the beam emittance of the 3.5-cell DC-SC photocathode injector developed at Peking University, a multi-slit emittance measure... Beam emittance is one of the most important parameters for electron sources. To investigate the beam emittance of the 3.5-cell DC-SC photocathode injector developed at Peking University, a multi-slit emittance measurement device has been designed and manufactured. The designed slit width, mask thickness and beamlet drift length are 100 ~m, 3 mm and 430 mm respectively. It is suitable for the electron beam with energy of about 5 MeV and the average current less than 0.1 mA. The preliminary measurement result of the rms emittance of the electron beam produced by the DC-SC injector is about 5 7 mm.mrad. 展开更多
关键词 emittance measurement multi-slit space charge effect DC-SC photocathode injector
原文传递
PIC mode simulation of solenoid collimation channel 被引量:2
12
作者 肖陈 原有进 +2 位作者 何源 刘勇 夏佳文 《Chinese Physics C》 SCIE CAS CSCD 2010年第8期1136-1139,共4页
A new SSC (Separated Sector Cyclotron)-Linac is being designed to serve as an injector for the SSC at the HIRFL (Heavy Ion Research Facility Lanzhou). The beam intensity at the LEBT (Low Energy Beam Transport) f... A new SSC (Separated Sector Cyclotron)-Linac is being designed to serve as an injector for the SSC at the HIRFL (Heavy Ion Research Facility Lanzhou). The beam intensity at the LEBT (Low Energy Beam Transport) for the heavy ions after the selection is typically low and the space charge effects are inconspicuous. The space charge effects become obvious when the beam current increases to a few hundred microamperes. The emittance growth deriving from the space charge effects may be particularly troublesome for the following linac and cyclotron. An optical system containing three solenoids has been designed for the LEBT to limit the beam emittance and to avoid the unnecessary beam loss in the cyclotron, as well as for the purpose of immunizing the LEBT emittance growth due to the space charge effects. The results of the PIC (Particle- In-Cell) mode simulation illustrate that this channel could limit the beam emittance growth and increase the beam brightness. 展开更多
关键词 PIC SOLENOID LEBT space charge effects COLLIMATOR
原文传递
Lie algebraic analysis and simulation of high-current pulsed beam transport in a solenoidal lens 被引量:2
13
作者 ZHANG Zhuo YANG Guo-Jun LU Jian-Qin 《Chinese Physics C》 SCIE CAS CSCD 2010年第1期134-137,共4页
Recent calculations of the transport of a high-current beam in a solenoidal lens have made progress to the second order with the Lie algebraic method. A review of the theory and our simulation to realize it will be de... Recent calculations of the transport of a high-current beam in a solenoidal lens have made progress to the second order with the Lie algebraic method. A review of the theory and our simulation to realize it will be described. Then we will present the results of simulation. A brief discussion on the space charge effect's contribution to the transportation will also be made. 展开更多
关键词 solenoidal lens Lie algebraic space charge effect NONLINEARITY
原文传递
Physical design of a 10 MeV LINAC for polymer radiation processing 被引量:2
14
作者 冯光耀 裴元吉 +4 位作者 王琳 张善才 吴丛凤 金凯 李为民 《Chinese Physics C》 SCIE CAS CSCD 2009年第S2期135-138,共4页
In China, polymer radiation processing has become one of the most important processing industries. The radiation processing source may be an electron beam accelerator or a radioactive source. Physical design of an ele... In China, polymer radiation processing has become one of the most important processing industries. The radiation processing source may be an electron beam accelerator or a radioactive source. Physical design of an electron beam facility applied for radiation crosslinking is introduced in this paper because of it’s much higher dose rate and efficiency. Main part of this facility is a 10 MeV travelling wave electron linac with constant impedance accelerating structure. A start to end simulation concerning the linac is reported in this paper. The codes Opera-3d, Poisson-superfish and Parmela are used to describe electromagnetic elements of the accelerator and track particle distribution from the cathode to the end of the linac. After beam dynamic optimization, wave phase velocities in the structure have been chosen to be 0.56, 0.9 and 0.999 respectively. Physical parameters about the main elements such as DC electron gun, iris-loaded periodic structure, solenoids, etc, are presented. Simulation results proves that it can satisfy the industrial requirement. The linac is under construction. Some components have been finished. Measurements proved that they are in a good agreement with the design values. 展开更多
关键词 radiation crosslinking travelling wave linac space charge effect beam loading effect
原文传递
A Particle-in-cell scheme of the RFQ in the SSC-Linac 被引量:1
15
作者 肖陈 何源 +9 位作者 陆元荣 Yuri Batygin 尹苓 玉志军 原有进 刘勇 常玮 杜小楠 王智 夏佳文 《Chinese Physics C》 SCIE CAS CSCD 2010年第11期1749-1753,共5页
A 52 MHz Radio Frequency Quadrupole (RFQ) linear accelerator (linac) is designed to serve as an initial structure for the SSC-Linac system (injector into Separated Sector Cyclotron).The designed injection and ou... A 52 MHz Radio Frequency Quadrupole (RFQ) linear accelerator (linac) is designed to serve as an initial structure for the SSC-Linac system (injector into Separated Sector Cyclotron).The designed injection and output energy are 3.5 keV/u and 143 keV/u,respectively.The beam dynamics in this RFQ have been studied using a three-dimensional Particle-In-Cell (PIC) code BEAMPATH.Simulation results show that this RFQ structure is characterized by stable values of beam transmission effciency (at least 95%) for both zerocurrent mode and the space charge dominated regime.The beam accelerated in the RFQ has good quality in both transverse and longitudinal directions,and could easily be accepted by Drift Tube Linac (DTL).The effect of the vane error and that of the space charge on the beam parameters have been studied as well to define the engineering tolerance for RFQ vane machining and alignment. 展开更多
关键词 RFQ PIC mode parameters sweep analysis manufacturing error space charge effect
原文传递
Lie algebraic analysis for the nonlinear transport of intense bunched beam in electrostatic quadrupoles 被引量:1
16
作者 张卓 吕建钦 《Chinese Physics C》 SCIE CAS CSCD 北大核心 2008年第3期209-214,共6页
In this paper, the nonlinear transport of intense bunched beams in electrostatic quadrupoles is analyzed using the Lie algebraic method, and the results are briefly presented of the linear matrix approximation and the... In this paper, the nonlinear transport of intense bunched beams in electrostatic quadrupoles is analyzed using the Lie algebraic method, and the results are briefly presented of the linear matrix approximation and the second order correction of particle trajectory in the state space. Beam having K-V distribution and Gaussian distribution approximation are respectively considered. A brief discussion is also given of the total effects of the quadrupole and the space charge forces on the evolution of the beam envelope. 展开更多
关键词 electrostatic quadrupole space charge effect Lie algebraic nonlinearity
原文传递
Longitudinal beam dynamic design of 500 kW beam power upgrade for CSNS-II RCS 被引量:1
17
作者 Hanyang Liu Sheng Wang 《Radiation Detection Technology and Methods》 CSCD 2022年第3期339-348,共10页
Purpose The accelerator of the China Spallation Neutron Source(CSNS)consists of an 80 MeV H-linac and a 1.6 GeV rapid cycling synchrotron(RCS).The design beam power is 100 kW,which has been reached.In the upgrade proj... Purpose The accelerator of the China Spallation Neutron Source(CSNS)consists of an 80 MeV H-linac and a 1.6 GeV rapid cycling synchrotron(RCS).The design beam power is 100 kW,which has been reached.In the upgrade project(CSNS-II),the beam power will be upgraded to 500 kW by increasing the linac energy to 300 MeV and adding a dual harmonic RF system in the RCS.In order to alleviate space charge effect and improve beam quality,the longitudinal beam dynamic of CSNS-II RCS dual harmonic RF system has been studied.Methods According to the longitudinal beam dynamic characteristics of CSNS-II RCS at different acceleration stages,the longitudinal emittance,bunching factor,momentumfilling factor and bunch length are studied and optimized in this paper.Results and conclusions The optimized bunching factor is greatly improved,and the tune spread caused by space charge effect is greatly reduced in CSNS-II.With the suppressed space charge effects,the beam loss can be well controlled in CSNS-II RCS. 展开更多
关键词 CSNS-II space charge effect Dual-harmonic RF systems Longitudinal beam dynamics RCS
原文传递
Preliminary design and simulation of a 162.5 MHz high-intensity proton RFQ for an accelerator driven system
18
作者 肖陈 何源 +9 位作者 刘勇 原有进 王志军 贺守波 徐孟鑫 李超 岳伟明 常玮 赵红卫 夏佳文 《Chinese Physics C》 SCIE CAS CSCD 2011年第11期1053-1058,共6页
A new procedure for the design and simulation of a Radio Frequency Quadrupole (RFQ) accelerator has been developed at the Argonne National Laboratory. This procedure is integrated with the beam dynamics design code ... A new procedure for the design and simulation of a Radio Frequency Quadrupole (RFQ) accelerator has been developed at the Argonne National Laboratory. This procedure is integrated with the beam dynamics design code DESRFQ and the simulation code TRACK, which are based on three-dimensional field calculations and the particle-in-cell mode beam dynamics simulations. This procedure has been applied to the development of a 162.5 MHz CW RFQ which is capable of delivering a 10 mA proton beam for the Accelerator Driven System (ADS) of the CAS. The simulation results show that this RFQ structure is characterized by the stable values of the beam acceleration efficiency for both the zero current beam and space charge dominated beam. For an average beam current of 10 mA, there is no transverse rms emittance growth, the longitudinal rms emittance at the exit of RFQ is low enough and there is no halo formation. The beam accelerated in the RFQ could be accepted easily and smoothly by the following super-conducting linear accelerator. 展开更多
关键词 RFQ DESRFQ TRACK ADS space charge effect
原文传递
Emittance-dominated long bunches in dual harmonic RF system
19
作者 安世忠 Klaus Bongardt +2 位作者 Rudolf Maier 唐靖宇 张天爵 《Chinese Physics C》 SCIE CAS CSCD 北大核心 2008年第1期60-66,共7页
The storage of long bunches for long time intervals needs flattened stationary buckets with a large bucket height. The longitudinal motion of the initially mismatched beam has been studied for both the single and dual... The storage of long bunches for long time intervals needs flattened stationary buckets with a large bucket height. The longitudinal motion of the initially mismatched beam has been studied for both the single and dual harmonic RF systems. The RF amplitude is determined to be r.m.s wise matched. The bucket height of the single harmonic system is too small even for shorter bunch with only 20% increased energy spread. The Halo formation and even debunching can be seen after a few synchrotron periods for single particles with large amplitude. In the case of small energy spread for a cooled beam, Coulomb interaction cannot be ignored. The external voltage has to be increased to keep the r.m.s bunch length unchanged. The new voltage ratio R(N) simplifies physics for the emittance-dominated bunches with modest particle number N. For the single harmonic system, substantial amount of debunching occurs without increasing the external voltage, but very little if the RF amplitude is doubled. Results from the ORBIT tracking code are presented for the 1 GeV bunch in the HESR synchrotron, part of the GSI FAIR project. 展开更多
关键词 bucket height MISMATCH space charge effect debunching
原文传递
Emittance measurement & optimization for the photocathode RF gun with laser profile shaping
20
作者 刘圣广 Masafumi Fukuda +2 位作者 Sakae Araki Nobuhiro Terunuma Junji Urakawa 《Chinese Physics C》 SCIE CAS CSCD 2010年第5期584-588,共5页
The Laser Undulator Compact X-ray source (LUCX) is a test bench for a compact high brightness X-ray generator, based on inverse Compton Scattering at KEK, which requires high intensity multi-bunch trains with low tr... The Laser Undulator Compact X-ray source (LUCX) is a test bench for a compact high brightness X-ray generator, based on inverse Compton Scattering at KEK, which requires high intensity multi-bunch trains with low transverse emittance. A photocathode RF gun with emittance compensation solenoid is used as an electron source. Much endeavor has been made to increase the beam intensity in the multi-bunch trains. The cavity of the RF gun is tuned into an unbalanced field in order to reduce space charge effects, so that the field gradient on the cathode surface is relatively higher when the forward RF power into gun cavity is not high enough. A laser profile shaper is employed to convert the driving laser profile from Gaussian into uniform. In this research we seek to find the optimized operational conditions for the decrease of the transverse emittance. With the uniform driving laser and the unbalanced RF gun, the RMS transverse emittance of a 1 nC bunch has been improved effectively from 5.46 πmm·mrad to 3.66 πmm·mrad. 展开更多
关键词 laser shaping space charge effect EMITTANCE photocathode RF gun
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部