低温高密核物质测量谱仪时间投影室的集团重建

Cluster Reconstruction for the CSR External-target Experiment(CEE) Time Projection Chamber

低温高密核物质测量谱仪(CEE)是研究高重子数密度区核物质性质的重离子碰撞实验谱仪。使用了先进的SAMPA电子学读出芯片的时间投影室(TPC)是CEE最核心的探测器。在集团重建的过程中,同一排读出板的信号被首先重建成2维集团,然后根据2维集团的ADC加权平均位置重建击中点。当信号ADC随漂移时间变化呈峰-谷-峰结构时,一个集团可能被重建成两个或更多击中点,从而提高双径迹分辨能力。使用模拟信号的测试显示,该重建算法在方向可以达到0.100/0.043 cm的位置分辨能力和1.1/2.8 cm的双径迹分辨能力。

The Cooler-Storage-Ring External-target Experiment(CEE) is a spectrometer to study the properties of nuclear matter at high baryon density region. The CEE time projection chamber, which uses the state-of-the-art SAMPA electronics read-out chips is the key sub-detector of CEE. Neighboring signals in the same pad row are first grouped together to form a 2-dimensional cluster. Then a hit is created for each cluster at the ADC weighted average signal position. A cluster may also be divided into two or more hits, when the signal ADC vs. time bin has a peak-valley-peak structure, in order to obtain better two-track separation ability. The performance of the algorithm, including 0.100/0.043 cm of hit resolution and 1.1/2.8 cm of double-track resolution in the direction, is also presented.