北京e/π试验束多丝室的能量分辨和位置分辨研究

Study on energy and position resolution of MWPC for the Beijing e/π test beam

本文描述了BEPC(北京正负电子对撞机)直线加速器附设e/π试验束多丝正比室的能量分辨和位置分辨研究。室采用阴极条感应读出分辨粒子位置,阳极信号作粒子能量分辨。对5.9keVγ,获得17%的能量分辨和0.24mm的位置分辨。对1.1GeV电子,得到0.3mm的位置分辨。分析了室制造中各种因素对室能量分辨的贡献,由此估计室的这一参数。研究了能量分辨随阳极高压的变化关系,发现存在能量分辨最小值,并与估计相吻合,文中还对其机理进行了讨论。

This paper describes the research on the energy and position resolution of the MWPC used in the e/π Test Beam on BEPC （Beijing Electron Positron Collider）, which localizes the particles of e/π by the readout method of gravity center of the induced charges on the cathode strips. The spatial resolution of about 0.24 mm and energy resolution of 17% for 5.9 keV γ photons are attained at the 3700 V anode voltage. For the 1.1 GeV electrons, the spatial resolution of 0.3 mm is obtained. The contributions of various factors to energy resolution are analysed. It is found that energy resolution is changed with the anode voltage and there exists a least energy resolution. The reasons for these are discussed.