Ren Haitao, Pozdeyev Eduard, Lund Steven M, Machicoane Guillaume, Wu Xiaoyu, Morgan Glenn
Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.
Rev Sci Instrum. 2016 Feb;87(2):02B919. doi: 10.1063/1.4934621.
To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper.
为满足稀有同位素束流装置（FRIB）碎裂靶处400 kW的束流功率要求，对于较重离子应采用双电荷态同时加速。这些强多电荷离子束将由一台28 GHz电子回旋共振（ECR）离子源在35 kV的高电压下产生。引出后，离子束将通过一个50 kV平台预加速至12 keV/u，传输至消色差电荷态选择（CSS）系统，随后经过一条垂直传输线，然后注入射频四极加速器。美国阿贡国家实验室（ANL）开发的TRACK代码用于对FRIB的ECR束流引出和低能束流传输进行模拟。在本研究中，我们将ECR离子源的磁场纳入模拟。针对ECR束流线测试了不同的初始束流条件以及不同的空间电荷中和水平。讨论了CSS系统中的束流损失及相应的保护措施。本文将给出关于CSS系统中束流动力学模拟和束流损失的详细结果。
