2005 Fiscal Year Final Research Report Summary
Development of High Resolution Homogeneous Calorimeter Using Liquid Xenon
| Project/Area Number |
16340064
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
MORI Toshinori The University of Tokyo, International Center for Elementary Particle Physics, Professor, 素粒子物理国際研究センター, 教授 (90220011)
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| Co-Investigator(Kenkyū-buntansha) |
HARUYAMA Tomiyoshi High Energy Accelerator Research Organization, Institute of Particle and Nuclear Studies, Professor, 素粒子原子核研究所, 教授 (90181031)
TERASAWA Kazuhiro WASEDA University, Advanced Research Institute for Science and Engineering, Lecturer, 理工学総合研究センター, 講師 (10329138)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Elementary particle physics / calorimeter / Highly pure xenon / International collaboration / photomultiplier |
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| Research Abstract |
In this scientific research project we have developed high resolution homogeneous calorimeter using liquid xenon.
This new type of calorimeter uses liquid xenon as the active medium that emits UV scintillation lights upon incidence of gamma rays and electrons. A number of photomultiplier tubes (PMTs) surrounding the liquid xenon measure these scintillation lights. The calorimeter does not contain any passive material like electrodes in the liquid xenon volume, thus can fully observe all the energy deposits.
We mostly concentrated on developments of various technologies necessary to realize a large volume (an order of 1,000 liters or 3 tons) detector.
Liquid xenon as the detector medium is guaranteed to be perfectly uniform, however, some impurity contamination, if it exists, absorbs the scintillation light and could deteriorate the performance of such a large volume device. We successfully developed a new, efficient purification method to remove impurities very quickly by circulating liqu
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id xenon through molecular sieves using a cryogenic centrifugal liquid pump. We also developed methods and techniques for xenon transfer, xenon pressure/temperature control, safety precaution, etc. These are necessary for practical application of a large volume liquid xenon detector.
We examined the performance of a liquid xenon detector by using π^0 decays. In this test we collected waveform data of PMTs and proved that we can distinguish incident gamma-rays from alpha particles. We also succeeded in developing a new type of PMTs with photocathode and base circuit that can sustain very high background rates even at low temperatures. Computer codes were developed to simulate the detector response and were shown to agree very well with the observed data.
An avalanche photodiode (APD) was operated and tested in liquid xenon. The APD is very compact and has a very high quantum efficiency. The success of this test opened up extensive future applications such as monitoring of absorption length. Less
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