Development of Reactor Neutrino Detector for Measurement of Neutrino Mixing Angle Theta_13

用于测量中微子混合角Theta_13的反应堆中微子探测器的研制

基本信息

批准号：
16204015
负责人：
SUEKANE Fumihiko
金额：
$ 31.95万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16204015/
关键词：
Neutrino Neutrino Oscillation Nuclear Reactor Liquid Scintillator KASKA CP非対称性

项目摘要

The aim of this research is to develop a reactor neutrino detector to measure neutrino mixing angle theta_13 accurately. In order to accurately measure the mixing angle theta_13, it is necessary to develop a detector with accurately known detection efficiency. Further more it is necessary to place such detectors near the reactor (〜a few 100m) and at oscillation maximum (〜1.6km) to cancel systematic uncertainties by comparing two detector data. As R&D for the detector the following studies were performed.1. A boring study was performed at an actual detector position in the site of the power station. The gamma-ray background and cosmic-ray background were measured at the actual depth where the detector is planned to locate. Simulators are developed based on such data and detector structure and depth are designed using the simulators. The information of geology is used to investigate about possible method of digging the underground area.2. A prototype detector, which consists of 900 liter liquid scintillator and 7 liters of Gadolinium loaded liquid scintillator. Neutrino like signals were generated by using Am-Be radioactive source and detection efficiency for the reactor neutrino events are studied. Especially, Gadolinium gamma ray peak was successfully observed which can not be observed in a small test system.3. KASKA will use 1200 photomultipliers. Test experiments for some candidate PMTs were performed, such as uniformity of the response, timing resolution, etc. and 10 inch PMT was selected for the KASKA experiment.Other R&D such as stability test of liquid scintillator, development of front end electronics, wire based detector calibration system.Finally letter of intent for the KASKA experiment is written based on those research.

本研究的目的是开发一种精确测量中微子混合角theta_13的反应堆中微子探测器。为了精确测量混合角theta_13，需要开发一种具有准确已知探测效率的探测器。此类探测器靠近反应堆（约几百米）并处于振荡最大值（约1.6公里），通过比较两个探测器数据来消除系统不确定性。作为探测器的研发，进行了以下研究。 1. 在电站现场的实际探测器位置进行了钻孔研究，在计划开发探测器的实际深度处测量了伽马射线背景和宇宙射线背景。基于这些数据，利用模拟器设计了探测器的结构和深度，用于研究挖掘地下区域的可能方法。2．原型探测器，由900升液体闪烁体和7升液体闪烁体组成。利用Am-Be放射源产生钆类中微子信号，研究了反应堆中微子事件的探测效率，特别是成功地观测到了小型测试系统中无法观测到的钆伽马射线峰。 3． KASKA将使用1200个光电倍增管对一些候选PMT进行测试实验，如响应均匀性、定时分辨率等，并选择10英寸PMT。液体闪烁体的稳定性测试、前端电子器件的开发、基于线的探测器校准系统等其他研发。最后根据这些研究撰写了KASKA实验的意向书。