Collaborative Research: Development of a Particle Tracking System for the Qweak Experiment

俄亥俄州大学将为杰斐逊实验室的Qweak实验设计和建造两套制冷机。这个重要的新实验将测量质子的弱电荷，作为对弱混合角运行的精确测试，从而提供了超越粒子物理标准模型的独特灵敏的物理探针。 触发振荡器是Q弱粒子跟踪系统的重要组成部分，在校准和背景测量过程中将用于启动电子和否决中性粒子。 每个闪烁体的尺寸为225 cm x 16 cm x 1 cm，由BC408或其等同物制成。 每端的非UVT光导将提供机械可靠的光学耦合接头。 UVT棒是5.1厘米直径和5厘米长将耦合矩形光导光电倍增管。闪烁器的长边将进行金刚石研磨，末端将进行600目砂光处理。 考虑到厚度与长度的极端比例，闪烁计数器必须由一个框架支撑，然后安装到后腔体封装。 为了减少辐射损伤，在大电流运行模式下，将从束的直接视野中移除该组件。 探测器的组装和测试将在俄亥俄大学核与粒子物理研究所由一名研究生和至少一名本科生在Opper教授的监督下完成。 俄亥俄州大学的研究小组也将开发这项实验所需的快速触发系统。 当探测器已被认为准备安装，学生将参加他们在杰斐逊实验室的调试。

Ohio University will design and build two sets of triggerscintillators for the Qweak experiment at Jefferson Lab. Thisimportant new experiment will measure the weak charge of the proton,as a precision test of the running of the weak mixing angle, thusproviding a uniquely sensitive probe of physics beyond the StandardModel of particle physics. The trigger scintillators are an essential component of the Qweakparticle tracking system, and will be used to start the electronicsand to veto neutral particles during the calibration and backgroundmeasurements. Each scintillator will be 225 cm x 16 cm x 1 cm andmade from BC408 or its equivalent. Non-UVT lightguides at each endwill provide a mechanically reliable optical coupling joint. UVT rodsthat are 5.1 cm in diameter and 5 cm long will couple the rectangularlightguide to the photomultiplier tubes. The long edges of thescintillators will be diamond milled and the ends finished to a 600grit sanded finish. Given the extreme ratio of thickness to length,the scintillator counters must be supported by a frame which is thenmountable to the rear chamber package. To reduce radiation damage,this package will be removed from direct view of the beam for the highcurrent running mode. The assembly and testing of the detectors will be done at the OhioUniversity Institute for Nuclear and Particle Physics by a graduatestudent and at least one undergraduate student, under the supervisionof Professor Opper. The Ohio University group will also develop the fast triggering system which is required for this experiment. When the detectors have been deemed ready for installation, the students will participate in their commissioning at Jefferson Lab.