【作者】 王海云； 祁辉荣； 刘凌； 原之洋； 张建； 陈元柏； 欧阳群；

【Author】 WANG Hai-yun;QI Hui-rong;ZHANG Yu-lian;WEN Zhi-wen;ZHANG Jian;CHEN Yuan-bo;OUYANG Qun;State Key Laboratory of Particle Detection and Electronics;Institute of High Energy Physics, Chinese Academy of Sciences;Graduate University of Chinese Academy of Sciences;School of Nuclear Science and Technology, Lanzhou University;

【机构】 核探测与核电子学国家重点实验室； 中国科学院高能物理研究所； 中国科学院大学； 兰州大学核科学与技术学院；

【摘要】 在高精度气体径迹探测器研究中,利用激光光束进行刻度和标定是一种重要的标定方法。激光标定利用双光子电离物理机制,使探测器工作气体内的杂质气体发生电离,产生可测量的电离信号。为确定激光标定中的激光优化设计参量,需要对不同光斑面积激光信号进行优化测试研究。本论文针对该问题,主要模拟研究和分析了探测器在工作气体(Ar/CO2=70/30)中,激光光斑尺寸与激光电离信号的关系。同时设计了激光信号测试光路以及不同宽度条的读出探测器,为优化光束质量,采用激光扩束镜进行扩束,使得光斑分布更加均匀。本论文实验测量了不同光斑面积与激光电离信号的关系,结果表明:对于266nm激光束,探测器增益在5000、前放增益为10mV/fC、光斑直径5mm激光能量为170μJ且扩束三倍时,选取光斑面积1mm2,读出条宽度2mm输出信号幅度约126mV,读出条宽6mm时输出信号幅度约400mV。将实验结果与模拟结果进行对比,信号大小满足现有的实验测量需求。论文最后还给出了激光功率密度扩束前后的对比结果,该研究为激光分束设计提供很好的实验参量。更多还原

【Abstract】 In the high resolution gaseous tracker detector R&D, it’s a very important calibration method used the UV laser beam. By the 2-photons ionization mechanism, the UV laser beams could produce the primary ionization tracks in the operation gas with the few impurities gases and the signal could be measured. Aimed to the optimization of the laser beam parameter, the signal should be studied with the different laser beam size. In this paper, the simulation and evaluation results of the signal with the specific laser beam size were given in the working gas of Ar/CO2=70/30. The triple-GEMs detector has been developed with the different width strips as readout pads, and the test laser map has been designed. To optimize the profile of the laser beam, the laser expander device used. The laser beam signals were measured with the different beam size or area, and the results indicate that the output signal from the preamplifier can achieve 126 mV with 2 mm width strip and 360 mV with 6 mm(For the 266 nm laser beam with energy density:1μJ/mm~2, the gain of the detector :5000, and the gain of the preamplifier: 10 mV/fC and the laser area: 1mm~2. The measurement signal could meet the most gaseous tracker detector requirement. Finally, the comparative profiles with and without the laser expander device were described. All will give the strongly support to design the specific parameter of the laser beam for the gaseous tracker detector in lab.更多还原