Search for galactic dark matter and double beta decay measurement using a detector of new principle

使用新原理探测器寻找星系暗物质和双β衰变测量

基本信息

批准号：
04402005
负责人：
MINOWA Makoto
金额：
$ 23.17万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1995
项目状态：
已结题

项目摘要

A dedicated dilution refrigerator has been constructed. It is capable of cooling the detector material down to 10mK.It is made of specially selected raw materials to reduce natural radiation background from them.In order to manufacture thermistors with high sensitivities at low temperature, neutron transmutation doping method was adopted.Neutron irradiation has been done at the JRR-3 reactor of the Japan Atomic Energy Reasearch Institute.Using these building elements, we developed cryogenic particle detectors consisting of 8 pieces of 20-gram lithium fluoride bolometers. The lithium fluoride is known to be the material which has the largest cross section for the detection of spin dependently interacting supersymmetric neutralinos. With these detectors a direct experimental search for supersymmetric particle dark matter has been performed and is still ongoing in the Nokogiri-yama underground cell of the institute for the Cosmic Ray Research, University of Tokyo.On the basis of a pilot run, limits were obtained on normalized point-like cross section for the spin-dependently interacting neutralino incident on a single proton, although the dark matter is not yet deiscovered.While the shielding against back-ground radiation is not fully optimized yet, our search gave the worls best limits for the spin-dependently interacting neutralino with a mass lower than 5 GeV.It demonstrates the advantages of using the fluorine for the target and the low energy threshold of the bolometer. Thwe search continues with the improved shielding and more efficient veto counters.

已经建造了专用的稀释冰箱。它能够将探测器材料冷却至10MK。它是由特殊选择的原材料制成的，以减少它们的自然辐射背景。为了在低温下制造高灵敏度的热敏电阻，采用了中子透射掺杂方法。中子辐射是在日本原子能促进的JRR-3反应器中进行的，这些构造的构造是在jrr-3反应器中进行的。 20克氟锂强仪。已知氟化锂是具有最大的横截面的材料，用于检测旋转依赖性相互作用的超对称中性诺斯。使用这些探测器，已经进行了直接进行超对称粒子暗物质的直接实验搜索，并且仍在诺科吉里族 - 雅玛（Nonokogiri-Yama）地下细胞中进行宇宙射线研究所的地下细胞，东京大学（University of Tokyo）。背景辐射尚未完全优化，我们的搜索为旋转依赖性相互作用的中性诺提供了最佳限制，其质量低于5 GEV。它证明了将氟用于靶标和bol计的低能量阈值的优点。随着改进的屏蔽和更有效的否决柜台，搜索继续进行。