RIBLL2上放射性次级束粒子鉴别能力的提升  

Improving the Particle Identification of Radioactive Isotope Beams at the RIBLL2 Separator

作　　者：方芳[1,2] 唐述文 王世陶[1,2] 章学恒 孙志宇[1,2] 余玉洪 阎铎[1,2] 金树亚 赵亦轩[1,2] 马少波 张永杰[1,2] FANG Fang;TANG Shuwen;WANG Shitao;ZHANG Xueheng;SUN Zhiyu;YU Yuhong;YAN Duo;JIN Shuya;ZHAO Yixuan;MA Shaobo;ZHANG Yongjie(Institute of Modern Physics,Chinese Academy of Science,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院近代物理研究所,兰州730000 [2]中国科学院大学,北京100049

出　　处：《原子核物理评论》2022年第1期65-72,共8页Nuclear Physics Review

基　　金：Upgrade Program for Infrastructure of Large Scale Facilities,CAS(DSS-WXGZ-2018-0002);Youth Innovation Promotion Association of Chinese Academy of Sciences(2018449);Open Research Project of Chinese Academy of Sciences,National Natural Science Foundation of China(U1732137,U1832122,U1738205)。

摘　　要：为了提升兰州重离子加速器冷却存储环(HIRFL-CSR)中放射性次级束流装置(RIBLL2)的粒子鉴别能力,在其F1色散面上研发、安装了一套可测量核反应产物起始时间和位置等信息的新型高性能探测器,并发展了一种利用测量的位置及飞行时间等实验数据提取束线光学参数从而修正粒子磁刚度的实验方法。使用F1色散面上的新型探测器,再结合粒子磁刚度修正方法,首次在RIBLL2-ETF分离器上实现了全动量接收度下300 MeV/nucleon ^(78)Kr弹核碎裂产物的清楚鉴别,结果显示:对于较重的^(75)As^(33+),其电荷分辨sZ~0.19、质核比分辨s_(A/Z)~5.8×10^(−3)。这一结果,有效提升了RIBLL2粒子鉴别能力,增加了奇异核收集效率,使研究范围由低质量核区(A<40)拓展到了中等质量核区(A~80),这将有效促进RIBLL2上放射性次级束物理实验的发展。To improve the ability of particle identification of the RIBLL2 separator at the HIRFL-CSR complex,a new high-performance detector for measuring fragment starting time and position at the F1 dispersive plane has been constructed and installed,and a method for achieving precise Bρ determination has been developed using the experimentally derived ion-optical transfer matrix elements from the measured position and ToF information.Using the high-performance detectors and the precise Bρ determination method,the fragments produced by the fragmentation of ^(78)Kr at 300 MeV/nucleon were identified clearly at the RIBLL2-ETF under full momentum acceptance.The atomic number Z resolution of sZ~0.19 and the mass-to-charge ratio A/Q resolution of sA/Q~5.8×10^(−3)were obtained for the^(75)As^(33+)fragment.This great improvement will increase the collection efficiency of exotic nuclei,extend the range of nuclei of interest from the A<40 mass region up to the A~80 mass region,and promote the development of radioactive nuclear beam experiments at the RIBLL2 separator.

关 键 词：RIBLL2 放射性次级束 粒子鉴别 

分 类 号：O571.4[理学—粒子物理与原子核物理]