Particle separation of high energy neutral beam using sampling calorimeter

本研究的目的是发展一种可靠的中性粒子分离方法。我们提出的量热计由闪烁和切伦科夫辐射材料的交替层组成。前者对各种带电粒子都很敏感，后者只对GeV范围内的高速（接近光速）类粒子电子敏感。在2003财年，我们制备了42个用于切伦科夫辐射器的石英模块和36层用于闪烁辐射器的塑料闪烁体模块，并进行了组装。这是第一阶段的原型，我们称之为BA 1。2004年2月至6月，在KEK 12-GeV质子同步加速器东计数器大厅对BA 1进行了中性束曝光，以检查其性能。通过这个测试，我们发现可以使用t ...更多信息 电磁簇射的纵向发展以及石英和塑料闪烁体信号之间的相关性，用于分离伽马和中子。由于我们已经观察到闪烁体信号由于辐射损伤而退化，我们在2004财政年度开始准备升级探测器BA 2。我们将塑料闪烁体改为PWO（铅钨氧化物），这是一种闪烁晶体和抗辐射材料。在BA 2中，闪烁层在横向方向上被分割，以观察电磁簇射的横向扩展，这可能为粒子分离提供另一信息。此外，BA 1中必须使用的铅板被移除，因为PWO足够重，可以在探测器内产生电磁簇射。我们在2004财政年度准备了所有的探测器部件，并将在2005年10月开始曝光。虽然大部分工作在本资助期间已经成功完成，但我们还不能完成研究，遗憾的是，我们的结果还没有发表。这是因为它需要时间来分析许多数据。我们的最终结果可能会在2006年公布。少

The purpose of this research, is to develop a sure method of neutral particle separation using sampling calorimeter. The calorimeter, which we proposed, consists of alternative layers of scintillation and Cherenkov radiation materials. The former is sensitive to all kinds of charged particles and the latter is only for the high speed (almost near to light speed) particle like electrons in GeV region. This method is expected to be applied to the detector in the high intensity neutral beam, and a high rate performance, including high tolerance to radiation, is another goal of this research.In Fy2003, we prepared 42 modules of quartz for the Cherenkov radiator and 36 layers of plastic scintillator for the scintillating radiators, and assembled. This is the first stage prototype, which we called BA1. BA1 was exposed to the neutral beam at the east counter hall of KEK 12-GeV proton synchrotron to check the performance from February to June 2004. By this test we found it is possible to use t … More he longitudinal development of electromagnetic shower as well as the correlation between quartz and plastic scintillator signals for the separation of gamma with neutrons.Since we already observed a degradation of scintillator signal due to radiation damage, we started to prepare the upgrade detector, BA2 in Fy2004. We changed the plastic scintillator to PWO (Lead-tungsten-oxide), which is a scintillating crystal and a radiation-hard material. In BA2, the scintillation layers are segmented in the lateral direction to see the lateral spread of electromagnetic shower, which might provide another information for the particle separation. Moreover, the lead sheet, which had to be used in BA1, were removed, because PWO is enough heavy to make an electromagnetic shower inside the detector. We prepared all of the detector parts in Fy2004, and will start an exposure in October 2005.Although the most of works have successfully done in the period of the present grant, we can not finalize the research and have not yet published our results, unfortunately. This is because it takes time to analyze many data. The publication of our final results might be in 2006. Less