ABOVEGROUND OBSERVATION OF DARK MATTER USING A CRYOGENIC PARTICLE DETECTOR

使用低温粒子探测器对暗物质进行地面观测

基本信息

批准号：
07640420
负责人：
WATANABE Tadashi
金额：
$ 1.22万
依托单位：
TOKYO UNIVERSITY OF INFORMATION SICENCES
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

By using a cryogenic detector with the target composed of about 344,000 tinmicrospheres of 0.0354g weight (in 30 micron diameter each), we have carried out a preliminary observation of dark-matter candidate particles in cosmic rays. It was performed at the temperature of 30mK and the applied field of 326 Gauss by use of the signal-readout system with a damped resonance circuit (the resonant frequency of about 1 MHz).By analysing the temporal spacings of signals and the pulse height, we confirmed what follows :(1) When an incident particle causes multiple spheres flip at a time, it is a charged cosmic one with certainty. For a single transition signal, however, we are unable to infer it whether due to the usual cosmic ray or a dark-matter particle without taking an event-coincidence procedure.(2) For the 5-micron variance of the size of the tin spheres used the super-heating superconducting field varies widely from 250 to 400G at 30mK,which reduces the effective mass of the target. The precision of the diameter within 1 micron is desired for the narrower allowance of the field.(3) The uniform distribution of the microspheres in the filling stuff is also critically important. A transition of a single sphere, one of the target ones in close vicinity each other, may trigger the nearest neighbor one and the chain reaction occurs successively. Provided that the first transition has owed to the very dark-matter particle, the resultant chain reaction is inferred to be caused by a charged particle.In conclusion, the particle detector based on the phase transition of the superheated superconducting spheres has some issues yet to overcome, the precise selection of the sphere size, the progress of the readout system with a higher sensitivity and the target of unifomly distributed spheres.

通过使用靶标的低温检测器，该靶标由约344,000个丁香球组成，重量为0.0354g（每个直径为30微米），我们对宇宙射线中的深色物质候选颗粒进行了初步观察。它是在30MK的温度和326高斯的应用场上进行的，它通过使用阻尼的共振电路（约为1 MHz的谐振频率）进行信号读取系统。通过分析信号的时间间距和脉冲高度的时间间距，我们确认了下面的粒子时，我们确认了以下粒子的粒子，请在一个seperty phere phite phere phere perip condecy condip condip condip condip condips comperty时，这是一个零件。但是，对于单个过渡信号，我们无法推断出它是否由于通常的宇宙射线或黑暗粒子而不采用事件偶然的程序。（2）对于锡球体的5微米差异，使用超热量超导管场的5微米差异，其范围为250至400g，在30mk上有250至400G的变化。对于田间的较窄余量，需要在1微米内的直径的精度。（3）填充物中微球的均匀分布也至关重要。单个球体的转变，一个彼此附近的目标的跃迁可能会触发最近的邻居一个，链反应依次发生。只要第一个过渡归功于非常黑暗的粒子，则最终的链反应是由带电的粒子引起的。结论，基于粒子探测器基于超热超导球的相位过渡，尚未克服某些问题，要克服的是镜头大小的精确选择，具有更高敏感性的读数系统的进度和距离spped of nififififififom of of of of of of of of of of of of of of of of spective。