北京谱仪端盖簇射计数器的建造与检测

描述了北京谱仪端盖簇射计数器的结构及制造工艺.并给出丝张力,暗电流、计数管工作特性等检测结果.     

利用宇宙线对BESⅢ量能器CsⅠ（Tl）晶体探测器单元的测量

利用宇宙射线进行探测器模型的性能测试是高能物理普遍采用的方法，其中最重要的步骤之一就是确定宇宙线入射的准确位置和径迹．多数采用丝室探测器来进行宇宙线的精确定位，需要很高的造价和复杂的电子学系统．本文介绍一种简单的定位方法，采用塑料闪烁体条加波移剂光纤编码读出的方式，可以实现精度为1cm的定位．据此建立了一套实验装置，对BESⅢ电磁量能器CsⅠ（Tl）晶体探测器单元的光输出强度和不均匀性进行了测量．     

基于阻性阳极读出方法的气体电子倍增器二维成像性能

新型微结构气体探测器,如气体电子倍增器(gas electron multiplier,GEM)等,具有非常好的位置分辨率潜力(σ100μm),但是需要匹配大规模高密度的读出电子学,给探测器的建设、造价、功耗、空间利用等带来极大压力.阻性阳极读出方法可以在保持较高位置分辨率的前提下,大幅节省电子学.基于厚膜电阻工艺,一种新的阻性单元阵列结构被成功开发和应用于三级级联GEM探测器的读出阳极.该阻性阳极包括6×6个6 mm×6 mm的基本阻性单元,仅需匹配49路读出电子学.~(55)Fe放射源(5.9 keV)和X光机(8 keV)实验的结果显示探测器的位置分辨率(σ)可好于80μm,位置非线性好于1.5%.同时,探测器还获得了很好的实物成像效果.探测器的优良性能表明这种阻性阳极读出方法适用于大面积二维成像气体探测器的读出,并可用于其他探测器的读出.     

Design and assembly of the CsI(Tl) crystal module of the BESⅢ electro-magnetic calorimeter

The CsI(Tl) crystal modules of the Beijing Spectrometer Ⅲ (BESⅢ) electro-magnetic calorimeter (EMC) were designed and assembled through Monte Carlo simulation and experiments. After the assembly was finished, the performance of each crystal module was tested by cosmic rays. All crystal modules were found to work well before the installation of EMC.     

Tuning of the cosmic-ray test system of the BESⅢ drift chamber

The BESⅢ drift chamber and its subsystems need a cosmic-ray test after the chamber construction to check the chamber construction quality,testing the joint operation of the whole system and the performance of the chamber.The noise performance,drift time and charge measurements,and the scanning of channels were examined specifically.The preliminary results of the test indicate that the whole system works well.     

Application of movable collimators to the BEPCⅡ

BEPCⅡ is a double ring e＋ecollider with high beam currents and luminosity,so the high beamrelated backgrounds may disturb the detector.In order to have a good quality of data taking,backgrounds should be kept at a level as low as possible.A series of collimators are designed and installed in both the e＋ and erings.Two of the collimators are horizontally movable,each for one ring,about 8 m upstream from the interaction point.Experiments have been done to identify the e-ectiveness of the movable collimators with different apertures and beam currents.The results show that the movable collimators are very effective and can reduce as much as about 50% of beam-related backgrounds.     

CsI（T1）晶体量能器中硅光二极管的核计数器效应研究

研究了由于电磁簇射在CsI（T1）晶体后端的泄漏而引起的硅光二极管“核计数器”效应．通过GEANT模拟和实验测量分析其在BESⅢ的CsI（T1）晶体量能器中对能量测量的影响．     

国产CsI(TI)晶体辐照损伤实验研究

研究了CsI(Tl)晶体在1.3GeV e^－束形成的电磁辐射场和⁶⁰Co γ辐射场照射后的辐照损伤,测量了晶体光输出和透射率的变化,以及辐射损伤的自然恢复和加热恢复效应.     

BESⅢ晶体量能器设计中的蒙特卡罗研究

在BESⅢ晶体量能器的设计、研制过程中,利用7×7CsI晶体探测单元的模拟程序,对其性能做了精细的蒙特卡罗研究.给出了与非相干噪声、能量线性、晶体光输出均匀性、位置依赖等相关的模拟结果.     

闪烁光纤特性测试

介绍了一套进行单根塑料闪烁光纤测量的实验装置,给出由这套装置获得闪烁光纤的光产额、衰减长度、时间分辨和位置分辨的实验方法和测量结果,并对两种不同厂家的光纤进行了比较.