JLab的A大厅里的高分辨谱仪安装了双层的铅玻璃量能器,用来做粒子鉴别分析.2008年初我们在美国的JLab获取了全部的CSR实验数据,这里采用了ROOT分析软件里的Fumili拟合方法和准弹性散射数据对位于高分辨谱仪上的量能器进行刻度.因为实验过程中硬件高压设置的变化,需要对CSR实验数据进行不同的对应的刻度.刻度结果表明此刻度修正是合适的.散射电子动量为1 GeV时,铅玻璃量能器对该能量粒子的最好分辨率为0.048 GeV.电子效率和pion介子拒绝度可以分别达到99.3%和99.8%.
Two layers of lead glass calorimeter are installed for additional PID analyses in each high resolution spectrometer (HRS) at Hall-A in Jefferson Lab (JLab). The Fumili minimization method of ROOT analysis software and quasi-elastic data of CSR experiment conducted by the authors in the early year of 2008 at JLab were used in the calibration of the calorimeter detector on HRS for the data analysis of CSR experiment. Since some high voltage changes in hardware settings, the lead glass calorimeter detector needed to be calibrated correspondingly. The calibration results are reasonable after this procedure. The best resolution of the calorimeter for the scattering electron was about 0. 048 GeV when its momentum was at 1.0 GeV after calibration. Total electron efficiency and pion rejection can reach 99.3% and 99.8%, respectively.