摘要
为提高样品测量效率,对MC-SNICS多靶位铯溅射负离子源进行了升级改进。改进后的离子源采用球面电离器代替原有的锥面电离器,对供铯系统也进行了比较彻底的改造,通过参数优化,12C-引出流强最大可达近150μA,比原有离子源提高了1倍以上。流强的提高增加了加速器的束载效应,导致纹波变大,对测量稳定性造成一定影响。通过增加主分析磁铁后的光阑孔径和优化束流传输,可使AMS保持高的测量精度,同时对测量本底未产生大的影响。
The MC-SNICS ion source of NEC compact AMS system at the AMS laboratory of Peking University was upgraded recently. Spherical ionizer and improved Cs reservoir were equipped with this upgraded ion source. 12C^- beam current up to 150μA can be obtained with careful optimization of operating parameters. Increased beam current causes bigger ripple of high voltage of tandem. To enlarge the diameter of the aperture downstream the analyzing magnet from 10 mm to 12 mm is helpful to keep the stability of the measurement. Experiment results show that background do not increase obviously with larger aperture.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2008年第B09期233-237,共5页
Atomic Energy Science and Technology
基金
国家科技支撑计划资助项目
