基于THGEM的切伦科夫粒子鉴别探测器研究

北京谱仪BESIII自2009年运行以来，在τ-charm能区取得了世界上最大的数据统计样本，并取得了四夸克态的发现等重大的物理成果。进一步精确检验低能QCD理论，对BESIII谱仪的PID粒子鉴别提出了更高的要求。BESIII利用dE/dx与TOF信息来进行PID粒子联合鉴别，对0.8GeV/c以下的低动量段π/K粒子鉴别能力较好。我们针对0.8GeV/c～1.5GeV/c高动量段的π/K粒子，在自制厚型气体电子倍增器(THGEM)取得成功的基础上，采用切伦科夫辐射进行粒子鉴别的方案，制作基于CsI光阴极的20cmX20cm的THEGM切伦科夫探测器样机。本项目的研究成果有助于提高高动量段的粒子鉴别效率，可直接应用在未来的对撞物理、重离子物理等实验上。

BESIII have accomplished a series of important physics results such as the discovery of pentaquark states since 2009. Now BESIII has accumulated the largest data sample at τ-charm energy region. A higher requirement on the particle identification (PID) needs to be met. Based on the thick gaseous electron multiplier (THGEM) developed by our group, we propose a Cherenkov detector based on THGEM with CsI photocathode coated to improve the π/K PID efficiency for the 0.8GeV/c ~ 1.5GeV/c momentum region. The result of this project can be directly used in collision physics, heavy ion collision physics and other physic topics.