Precision spectroscopy of Bi-210 as a basis for the detection of CNO-neutrinos

Bi-210 精密光谱作为 CNO 中微子检测的基础

• 批准号: 408339458
• 负责人: Professor Dr. Kai Zuber
• 金额: --
• 依托单位: Institut für Kern- und Teilchenphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/408339458?language=en
• 关键词: Precision; spectroscopy; Bi; 210; basis

A fundamental process of stellar energy production is the so called CNO-cycle. Even proposed in the 1930ies the associated CNO-neutrinos haven't been detected.In the last decade experiments based on liquid scintillators have been dominated solar neutrino research, especially the Borexino experiment which has studied various neutrino reates from the pp-cycle.For a first detection of CNO-neutrinos extreme low backgrounds is essential. One of the major backgrounds sources is the forbidden beta decay of Bi-210. It's spectral shape similarity of the electrons and correlations to the recoil spectrum of CNO is very hard to disentangle. As it is a forbidden decay the theoretical modelling is non-trivial. Hence, the aim of this grant application is to measure the spectral shape of the Bi-210 electrons with high precision. Based on work already performed, in a first step the beta allowed beta decay spectrum of Si-31 should be measured and the developed analysis tools will be checked and validated. In a second step is the precision measurement of the Bi-210 beta spectrum. The outcome of this measurement will be used to make sensitivity estimates for liquid scintillator detectors. In a final step the CNO-analysis including the measured spectroscopic spectrum of Bi-210 will be performed within the Borexino experiment.

恒星能量产生的一个基本过程就是所谓的hoc循环。即使在20世纪30年代提出了相关的hoc中微子也没有被探测到。在过去的十年里，基于液体闪烁器的实验一直是太阳中微子研究的主流，特别是Borexino实验，它研究了pp循环产生的各种中微子。其中一个主要的背景来源是Bi-210的禁戒β衰变。它与CNO的反冲谱的电子谱形相似性和相关性很难解开。由于它是一种禁止衰变，理论模型是不平凡的。因此，本授权申请的目的是以高精度测量Bi-210电子的光谱形状。根据已经完成的工作，第一步应测量Si-31的β允许β衰变谱，并检查和验证开发的分析工具。第二步是精确测量Bi-210 β谱。该测量的结果将用于对液体闪烁体探测器进行灵敏度估计。在最后一步中，将在Borexino实验中进行hoc分析，包括Bi-210的测量光谱。