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Research & development on advanced detectors for B-factories.

研究

基本信息

批准号：
05044063
负责人：
MATSUDA Takeshi
金额：
$ 2.88万
依托单位：
National Laboratory for High Energy Physics, KEK
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05044063/
关键词：
Asymmetric B-factory CP violation in B decays Silicon micro vertex detector Double-sided silicon strip detector Preamplifier VLSI with analog memory Particle identification Fast ring image Cherenkov counter CsI photocathod RICH

项目摘要

National Laboratory for High Energy Physics, KEK,is building an asymmetricB-factory. The goal of the peak luminosity is 10^<34> cm^<-2> sec^<-1.> The BELLE collaboration builds a detector to study of CP violation in B meson decays. It is shown by Monte Carlo studies based on the current design of the BELLE detector that a definitive test of CP violation in the standard model may be possible by measuring the three angles and the three sides of the CKM triangles. To realize this goal, a good measurement of the B decay vertices and a excellent pi/K identification up to 4 GeV/c are necessary. We plan to build a Silicon micro Vertex Detector (SVD) made of Double-sided Silicon Strip Detectors (DSSD) with a Double-Metal Layr (DML) for the z-strip readout. In this project, we studied the optimized design of SVD at the KEK/B-factory and successfully performed R&D studies on large DSSD with DML,SVD readout electronics including new 128 channel low noise preamplifier VLSI's with analog memory, a new wireless bonding method for DSSD.As a candidate of the pi/K identification device of the BELLE experiment, in this project we assumed a fast Ring Image Cherenkov (RICH) counter and performed a intensive R&D on it. We obtained the 3sigmapi/K separation up to 2.86 GeV/c for a full size prototype of the fast RICH counter using the LiF radiator and a TEA/CH_4 gas mixture. We then tested two prototype RICH counters with different CsI photocathodes. Both detectors were operated successfully in beams observing expected Cherenkov rings. However the quantum efficiency of the CsI photocathode was found to be only about 10% in both cases while we need the value larger than 15%.

国家高能物理实验室（KEK）正在建设一个不对称工厂。峰值亮度的目标是10^<34> cm^<-2> sec^<-1。BELLE合作建立了一个探测器来研究B介子衰变中的CP破坏。基于BELLE探测器现有设计的蒙特卡罗研究表明，可以通过测量CKM三角形的三个角和三个边来确定标准模型中的CP违逆。为了实现这一目标，必须对B衰变顶点进行良好的测量，并具有高达4 GeV/c的出色的pi/K识别。我们计划构建一个硅微顶点探测器（SVD），由双面硅条探测器（DSSD）和双金属层（DML）组成，用于z条读出。在本项目中，我们在KEK/ b工厂研究了SVD的优化设计，并成功地进行了带有DML的大型DSSD的研发研究，SVD读出电子器件包括新型128通道低噪声前置放大器VLSI模拟存储器，一种新的DSSD无线键合方法。作为BELLE实验pi/K识别装置的候选器件，本项目假设了快速环图像切伦科夫（RICH）计数器，并对其进行了深入的研发。我们使用LiF散热器和TEA/CH_4气体混合物，获得了快速RICH计数器全尺寸原型的3sigmapi/K分离高达2.86 GeV/c。然后，我们用不同的CsI光电阴极测试了两个原型RICH计数器。两个探测器都成功地在观测预期切伦科夫环的光束中运行。然而，在这两种情况下，CsI光电阴极的量子效率都只有10%左右，而我们需要大于15%的数值。