Calculation of neutron background for underground experiments
Calculation of neutron background for underground experiments
复制标题
地下实验中子本底计算
DOI：
10.1016/j.nima.2008.07.071
复制
发表时间：
2008
影响因子：
1.4
通讯作者：
M. Robinson
中科院分区：
文献类型：
--
作者：
V. Tomasello;V. Kudryavtsev;M. Robinson
新一代暗物质实验旨在探索WIMP-核子标量相互作用的10-9-10-10pb截面区。探测器组件中产生的中子是限制探测器灵敏度的主要因素之一。从这一来源估计本底成为设计未来大规模探测器的关键任务。探测器内部和周围的所有材料都需要放射性污染产生的中子的能谱和产生率。为了估计中子产额和能谱，(α，n)反应的截面和跃迁到不同激发态的几率应该是已知的。用EMPIRE2.19计算了几种同位素的截面和跃迁几率，并与实验数据进行了比较。用SOURCES4A程序计算了材料的中子谱。对基于Ge晶体的假想暗物质探测器的部分探测器部件的中子本底事件率进行了估算。根据这些模拟的结果，对材料的放射性纯度提出了一些要求。
New generation dark matter experiments aim at exploring the 10-9–10-10pb cross-section region for the WIMP–nucleon scalar interactions. Neutrons produced in the detector components are one of the main factors that can limit detector sensitivity. Estimation of the background from this source then becomes a crucial task for designing future large-scale detectors. Energy spectra and production rates for neutrons coming from radioactive contamination are required for all materials in and around the detector. In order to estimate neutron yields and spectra, the cross-sections of (α,n) reactions and probabilities of transitions to different excited states should be known. Cross-sections and transition probabilities have been calculated using EMPIRE2.19 for several isotopes, and for some isotopes, a comparison with the experimental data is shown. The results have been used to calculate the neutron spectra from materials using the code SOURCES4A. Neutron background event rates from some detector components in a hypothetical dark matter detector based on Ge crystals have been estimated. Some requirements for the radiopurity of the materials have been deduced from the results of these simulations.