北京谱仪Ⅱ顶点探测器的离线刻度

Offline Calibration of BES Ⅱ Vertex Chamber

介绍了在ＶＣＪＵＬＩ基础上对北京谱仪Ⅱ顶点探测器进行离线刻度的方 法，包括整体Ｔ０的获得、单丝零时间ｔ０的扣除、丝位的修正、顶点探测器相对 于主漂移室位置的校正以及漂移时间一漂移距离关系的修正等．并由此给出了 北京谱仪Ⅱ顶点探测器的主要参数：空间分辨好于１００μｍ．

An algorithm based on VCJULI to calibrate the BES Ⅱ vertex chamber is described. The calibration includes the determination of global T0, the subtraction of t0 shift for each wire, the corrections of wire position itself and the position of the vertex chamber relative to the main drift chamber, the establishment of drift time to drift distance relation, etc. The main performance of the BES Ⅱ vertex chamber is given accordingly: space resolution is better than 100μm.