共查询到10条相似文献,搜索用时 187 毫秒
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Lizhen Liang Jianglong Wei Chundong Hu 《Journal of Nuclear Science and Technology》2013,50(4):481-489
Detailed trajectories of the residual ion passing through a reflection magnet, which is installed in the Experimental Advanced Superconducting Tokamak (EAST) neutral beam injector (NBI) system to remove the residual ion from the beam path, are reported. Monte Carlo simulation has been performed to obtain estimations of the beam density on the high heat flux elements of reflection magnet. On magnet pole shielding, there are three high beam power density regions, resulting from beam line focus and corresponding to the full energy, half energy and third energy. These high heat flux regions will bring a serious challenge for steady-state operation. The simulation result indicates that the re-ionization loss is about 2.43% and the magnet pole shielding encounters a problem of beam line focus, which should be taken seriously during the steady-state operation. 相似文献
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高能同步辐射光源(HEPS)是计划在北京建造的发射度小于60 pm•rad的超低发射度光源。它由1台500 MeV直线加速器、1条500 MeV低能束流输运线、1台500 MeV~6 GeV的能量增强器、2条6 GeV的高能束流输运线、1台6 GeV的储存环以及同步辐射光束线和实验站组成。本文进行低能束流输运线的设计研究。低能束流输运线是连接直线加速器和增强器的束流传输线,在考虑建设布局限制的基础上,对两端的束流包络进行匹配,并将直线加速器产生的束流高效传输到增强器注入点。HEPS低能束流输运线设计时采用了功能分区的设计策略,设计有3个功能区,分别是消色散注入匹配区、光学参数匹配区、输出匹配区。为校正误差对束流的影响,HEPS低能束流输运线设置了8个BPM,水平和垂直各6块校正磁铁用于束流轨道校正,校正后的轨道满足束流传输要求。 相似文献
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YANG Yao LIU Zhanwen ZHANG Wenhui MA Hongyit ZHANG Xuezhen ZHAO Hongwei YAO Zeen 《核技术(英文版)》2012,(2):83-89
A 2.45 GHz electron cyclotron resonance intense proton source and a low energy beam transport line with dual-Glaser lens were designed and fabricated by Institute of Modern Physics for a compact pulsed hadron source at Tsinghua. The intense proton beams extracted from the ion source are transported through the transport line to match the downstream radio frequency quadrupole accelerator. Particle-in-cell code BEAMPATH was used to carry out the beam transport simulations and optimize the magnetic field structures of the transport line. Emittance growth due to space charge and spherical aberrations of the Glaser lens were studied in both theory and simulation. The results show that narrow beam has smaller aberrations and better beam quality through the transport line. To better match the radio frequency quadrupole accelerator, a shorter transport line is desired with sufficient space charge neutralization. 相似文献
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MALei SONGMing-Tao CAOYun ZHAOHong-Wei ZHANGZi-min LIXue-Qian LIJia-Cai 《核技术(英文版)》2004,15(6):352-355
In order to research multi-component ion beam transport process and improve transport efficiency, a special simulating program for ECR beam is becoming more and more necessary. We have developed a program written by Visual Basic to be dedicated to numerical simulation of the highly charged ion beam and to optimization of beam dynamics in transport line. In the program the exchange of electrons between highly charged ions and low charged ions or neutral atoms (residual gas in transport line) is taken into account, adopting classical molecular over-barrier model and Monte Carlo method, so the code can easily give the change of charge state distribution along the transmission line. The main advantage of the code is the ability to simultaneously simulate a large quantity of ions with different masses and charge states, and particularly, to simulate the loss of highly charged ions and the increase of low charged ions due to electron exchange in the whole transport process. Some simulations have been done to study the transmission line of LECR3 which is an ECR ion source for highly charged ion beam at IMP. Compared with experimental results, the simulations are considered to be successful. 相似文献
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我所质子静电加速器头部切割的10ns脉冲束流经加速成0.5至2.5MeV后,传输进入中子厅,或由高频扫描板扫开,经Mobley磁铁压缩成1—2ns脉冲束流,或由Mobley磁铁偏转,在距磁铁出口1.54米处得到一横截面为圆形的束斑。它的半径为2mm,最大散角为5mrad。如图1所示,为了利用大液体闪烁探测器测量快中子俘获截面,一个10ns脉冲束流传输系统 相似文献
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The transport characteristics of a space chargedominated multi-species deuterium beam consisting of D_1~+,D_2~+, and D_3~+ particles in an electrostatic low-energy beam line are studied. First, the envelope equations of the primary D_1~+ beam are derived considering the space charge effects caused by all particles. Second, the evolution of the envelope of the multi-species deuterium beam is simulated using the PIC code TRACK, with the results showing a significant effect of the unwanted beam on the transport of the primary beam. Finally, different injected beam parameters are used to study beam matching, and a new beam extraction system for the existing duoplasmatron source is designed to obtain the ideal injected beam parameters that allow a D_1~+ beam of up to 50 m A to pass unobstructed through the electrostatic low-energy beam transport line in the presence of an unwanted(D_2~+, D_3~+)beam of 20 m A; at the same time, distortions of the beam emittance and particle distributions are observed. 相似文献
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