Development of a Read-out System with a PWO based Electro-Magnetic Calorimeter for the ALICE Experiment at LHC

在CERN-LHC的ALICE实验中，我们成功地为光子谱仪(PHOS)研制了一种新的钨酸铅晶体的光子读出系统。PHOS是一种电磁量热计，由17,920个基于PWO晶体的探测器元件组成，旨在实现迄今为止建造的GeV粒子电磁量热计中最好的能量分辨率和最佳的双道分辨率。该读出系统由雪崩光电二极管、前置放大板、具有脉冲整形器、脉冲形态数字化、数字数据处理器、0级和1级触发处理器以及数据传输总线驱动器等多种功能的前端电子(FEE)板组成。APD板和前置放大板是在日本设计、测试和制造的。该雪崩光电二极管/前置放大器样品已用于256通道原型量热计，并于2005-06年在欧洲核子研究中心和欧洲核子研究中心进行了测试。它们表现出了良好的性能，如设计和初步批准的批量生产。费用板是与中央人民大学和武汉理工大学中国小组合作设计和测试的，因为他们是在费板批量生产中收费的。2005年5月对读出系统进行了技术审查，Toru Sugate介绍了其作为主讲人之一的状况和准备情况。整个系统的量产已于10月正式获得批准，助学金项目已经顺利完成，我们已经为PHOS的建设做好了准备。在这一成功成果的基础上，提出了一种新的助学金，用于建造PHOS探测器和通过大型强子对撞机爱丽丝的光子通道研究夸克-胶子-等离子体物理。

We have successfully developed a photon readout system of a newly developed lead-tungstate crystal for the Photon Spectrometer (PHOS) in the ALICE experiment at CERN-LHC. The PHOS is an electromagnetic calorimeter consisting of 17,920 channels of detector element based with a PWO crystal, and is designed to achieve the finest energy resolution and the best two-track resolution among EM-calorimeters for GeV particles so far built. The readout system is composed of an avalanche photo-diode (APD), a preamplifier board, a front-end electronics (FEE) board which is equipped with several functions of a pulse shaper, a pulse form digitizer, a digital data processor, a level-0 and -1 trigger processor, and a data transfer bus driver. The APD and preamplifier board has been designed, tested and fabricated in Japan. The APD/preamplifier sample has been used in a 256 channel prototype calorimeter and tested at CERN-PS and SPS in 2005-06. They showed an excellent performance as is designed and preliminary approved for mass-production. The FEE board was designed and tested in cooperation with groups from CCNU and WUST at Wuhan, China, since they are charged in the FEE board mass-production. A technical review of the readout system was held in May 2005, and Toru Sugitate presented its status and readiness as one of presenters. The approval for mass-production of the entire system has been officially given in Oct. The Grant-In-Aid project has then been successfully completed and we are ready for the PHOS construction. Based on this successful achievement, a new Grant-in-Aid has been proposed for a construction of the PHOS detector and studies of quark-gluon-plasma physics via the photon channel in ALICE at LHC.