搜索结果: 91-105 共查到“知识库 中子物理学”相关记录654条 . 查询时间(5.281 秒)
用中子活化分析镀膜厚度及其探测极限研究
镀膜厚度 中子活化 测量灵敏度
2011/8/22
本工作提出用中子活化分析有基底的单层或多层镀膜厚度的方法。用Am-Be中子源对Au、Al、Cu等薄膜活化后，用HPGe探测器测量被活化薄膜放出的特征γ射线全能峰面积，并用蒙特卡罗方法模拟计算HPGe探测器对不同特征γ射线的探测效率，得到用反应堆中子源活化分析不同元素镀膜厚度的方法和探测极限。与目前广泛使用的X射线荧光方法相比，其分析灵敏度可提高几个量级。
中子气泡探测器用于核测井中子个人剂量监测的研究
中子气泡探测器 核测井 中子个人剂量监测 场刻度
2011/8/22
为研究国产中子气泡探测器在核测井中子个人剂量监测中的适用性，采用国内研制的中子气泡探测器对核测井运源车外表面、车内兼用储源仓周围等关注点的中子辐射水平进行监测，同时采用进口LB6411型中子周围剂量当量仪进行比对监测。实验结果表明，当运源车兼用储源仓内仅装载中子源时，中子气泡探测器与LB6411的测量结果无显著统计学差异，两者测量结果符合较好，中子气泡探测器的测量结果准确可信；当兼用储源仓分别装载...
Neutrino masses and Neutrinoless Double Beta Decay: Status and expectations
Neutrino masses double beta decay
2010/3/15
Two most outstanding questions are puzzling the world of neutrino Physics: the possible Majorana nature of neutrinos and their absolute mass scale. Direct neutrino mass measurements and neutrinoless d...
K* resonance effects on direct CP violation in B -> pi pi K
K* resonance effects direct CP B -> pi pi K
2010/3/15
Charged and neutral B decays into two charged pions and a charged or a neutral kaon are analyzed within the QCD factorization scheme where final state interactions before and after hadronization are i...
大样品中子活化分析的理论依据和误差修正
大样品中子活化分析 热中子自屏蔽 γ射线自吸收 不均匀性
2011/8/17
中子活化分析（NAA）是最重要的核分析技术之一。目前，国内和国际上绝大多数NAA实验室只能对小样品（mg～g或μL～mL）进行分析。本工作概要介绍大样品中子活化分析的原理，重点介绍了由于体积增大而带来的中子注量率自屏蔽、γ射线自吸收等修正因子的算法，以及对样品不均匀性的修正方法。
MCNP程序用热中子散射数据制作和检验
ENDF/B-Ⅶ.0 热中子散射 MCNP 积分检验
2011/8/22
基于ENDF/B-Ⅶ.0评价库，以前已陆续研制了可供MCNP程序使用的连续截面库，以及多套多个温度、多组邦达连柯背景截面修正的多群参数库。本文采用NJOY程序以及ENDF/B-Ⅶ.0评价库热散射子库，完成了MCNP程序使用热中子散射数据库S(α，β)的制作和检验。比较了自制库与MCNP自带基于ENDF/B-Ⅵ版热散射数据库(sab2002)，对改进较明显的重要介质“轻水中氢”和“重水中氘”给出了分...
The research activities in collaboration with Enzo Flaminio are summarized and discussed.
Common Origin of Soft mu-tau and CP Breaking in Neutrino Seesaw and the Origin of Matter
Soft mu-tau Neutrino Seesaw CP Breaking
2010/3/15
Neutrino oscillation data strongly support mu-tau symmetry as a good approximate flavor symmetry of the neutrino sector, which has to appear in any viable theory for neutrino mass-generation. The mu-t...
Pairing gap energy correction in Shell model for the neutron-rich tin isotopes
132Sn region Oxbash code Effective interaction
2010/7/8
The region in the vicinity of 132Sn, gathering numerous isotopes of important masses, shows lots of interestsm for explaining the most interesting phenomena. It offers among others the possibility to ...
Multi-modal analysis for low energy neutron-induced fission of 235U
235U (n, f) multi-model prompt neutron fragment property
2009/12/24
Low energy neutron induced fission of 235U is studied in the framework of the multi-modal fission model. The fission fragment properties, such as the yields, the average total kinetic energy distribut...
Proposal for muon and white neutron sources at CSNS
high power proton beam pulsed muon source white neutron source muon science nuclear data measurements
2009/12/24
The China Spallation Neutron Source (CSNS) is a large scientific facility with the main purpose of serving multidisciplinary research on material characterization using neutron scattering techniques...
The possibility to detect fast neutrons with a multi-gap resistive plate chamber (MRPC) has been investigated. To detect fast neutrons, a thin polyethylene layer is coated on the surface of electrode ...
中子气泡探测器性能改进及初步检验
气泡探测器 剂量响应 重现性
2011/8/17
对自制中子气泡探测器进行了改进。对改进后探测器的个人中子剂量响应以及重现性、批内一致性在国防科学技术工业委员会放射性计量一级站的中子仪表刻度实验室进行了检验。结果显示，探测器的重现性、剂量响应和批内一致性等主要特性有了大幅提高。
低能α粒子与中子耦合输运模拟
耦合输运 中子产额 次级中子
2009/11/27
开发了低能α粒子与中子耦合输运程序，可以计算低能α粒子在各种介质中的输运、含氧介质中的（α，n）中子产额，跟踪次级中子。采用蒙特卡罗方法中带权重跟踪的技巧，通过大量小权重事件的模拟成功解决了低能（α，n）反应中子产额太低、无法直接模拟的困难。α粒子的射程与阻止本领用SRIM程序计算，（α，n）截面取自最新的JENDL带电粒子库，次级中子跟踪使用MCNP程序。