检索结果-南通市图书馆

电感耦合等离子体质谱法测定单晶铜中痕量放射性核素钍和铀的含量

在线全文

学校读者我要写书评

暂无评论

核技术 2018年第9期41卷 21-26页

作者：袁影王思广北京大学物理学院核物理与核技术国家重点实验室及高能物理研究中心北京100871

Panda X-Ⅲ实验位于中国锦屏极深地下实验室,将利用高压136Xe气体时间投影探测器进行无中微子双贝塔衰变事件的寻找。建造高灵敏度的大型探测器需要挑选放射性极低的高纯材料以对本底进行严格的控制。本工作应用电感耦合等离子体质谱(In... 详细信息

Panda X-Ⅲ实验位于中国锦屏极深地下实验室,将利用高压136Xe气体时间投影探测器进行无中微子双贝塔衰变事件的寻找。建造高灵敏度的大型探测器需要挑选放射性极低的高纯材料以对本底进行严格的控制。本工作应用电感耦合等离子体质谱(Inductively Coupled Plasma Mass Spectrometry,ICP-MS)法测定纯度极高的单晶铜中痕量钍和铀的含量。在样品消解前加入^(230)Th和^(235)U分别作为标记核素,样品经过8 mol·L-1 HNO_3消解后,依次通过TEVA和UTEVA树脂柱,实现待测核素^(232)Th、^(238)U与基体元素Cu的分离。利用同位素稀释法-ICP-MS测定^(232)Th和^(238)U的含量。通过空白样品实验测量,^(232)Th的检出限是0.036 pg(232Th)·g^(-1)(0.15μBq(232Th)·kg^(-1)),238U的检出限是0.070 pg(238U)·g^(-1)(0.86μBq(238U)·kg^(-1));单晶铜样品中232Th及238U的检出限分别是0.21 pg(^(232)Th)·g^(-1)(0.85μBq(232Th)·kg^(-1))和0.45 pg(238U)·g^(-1)(5.56μBq(238U)·kg^(-1))。该方法可为探测器建造过程中的材料选取工作提供技术支持。

关键词：电感耦合等离子体质谱单晶铜 TEVA UTEVA 痕量钍铀

用GPU加速信号形状与探测器分辨率随能量变化的卷积计算

在线全文

学校读者我要写书评

暂无评论

核技术 2018年第8期41卷 48-53页

作者：乔颢王思广北京大学物理学院核物理与核技术国家重点实验室及高能物理中心北京100871

在形如中微子能谱分析中,因其本征能谱跨度较大,在积分描述所探测到的能谱时,探测器分辨率本身随能量的连续变化应该被考虑。对于该类能谱的拟合分析,传统的单靠中央处理器(Central Processing Unit,CPU)无法保障时间要求。本文利用图... 详细信息

在形如中微子能谱分析中,因其本征能谱跨度较大,在积分描述所探测到的能谱时,探测器分辨率本身随能量的连续变化应该被考虑。对于该类能谱的拟合分析,传统的单靠中央处理器(Central Processing Unit,CPU)无法保障时间要求。本文利用图形处理器(Graphics Processing Unit,GPU)配合使用统一计算架构(Compute Unified Device Architecture,CUDA)和Roo Fit计算框架来加速数值积分过程,测试显示:当计算节点数目较多,如106个节点时,利用文中的方法 GPU(型号:K80)相较于CPU(型号:E5-2603 v3)能够带来218倍的速度提升。所述方法可作为类似实验的参考。

关键词：图形处理器卷积数值积分 RooFit 统一计算架构

CMGA:一个利用钚的94—104keV γ和X射线非破坏分析其同位素丰度的软件

在线全文

学校读者我要写书评

暂无评论

核技术 2006年第4期29卷 257-260页

作者：王思广冒亚军唐培家北京大学物理学院北京100871 中国原子能科学研究院北京102413

钚样品γ能谱94—104keV能区中有22条X及γ射线可用来提供其同位素丰度信息。本文介绍我们开发的用来解析该能区的CMGA1.0(ChinaMultipleGroupAnalysis,Version1.0)软件。利用该软件分析当前我们所能取得的唯一的具有质谱分析结果的样... 详细信息

钚样品γ能谱94—104keV能区中有22条X及γ射线可用来提供其同位素丰度信息。本文介绍我们开发的用来解析该能区的CMGA1.0(ChinaMultipleGroupAnalysis,Version1.0)软件。利用该软件分析当前我们所能取得的唯一的具有质谱分析结果的样品。其240Pu/(239Pu+240Pu)多次测量的平均值与质谱法给出的对应数值之比为1.004,相对标准偏差为1.4%。

关键词：钚同位素丰度多道γ能谱非破坏分析

在线全文

学校读者我要写书评

暂无评论

多道γ能谱的精细分析

核技术 2006年第7期29卷 495-498页

作者：王思广冒亚军唐培家李泽北京大学物理学院北京100871 中国原子能科学研究院北京102413

本文描述一种综合考虑放射性核素中各γ射线之间的由分支比给出的强度比值及相对探测效率进行拟合从而给出最优化结果的解谱方法。同时给出对本底描述的函数。利用该方法进行样品中各放射性核素的含量分析时,可以合并分析步骤,降低误差... 详细信息

本文描述一种综合考虑放射性核素中各γ射线之间的由分支比给出的强度比值及相对探测效率进行拟合从而给出最优化结果的解谱方法。同时给出对本底描述的函数。利用该方法进行样品中各放射性核素的含量分析时,可以合并分析步骤,降低误差积累。

关键词：同位素丰度多道γ能谱非破坏分析数据分析

X射线峰形描述技术及分支比约束在解谱中的应用

在线全文

学校读者我要写书评

暂无评论

核技术 2015年第2期38卷 50-55页

作者：王思广韦江波张欢北京大学物理学院核物理及核技术国家重点实验室北京100871

尽管多道能谱中X射线与γ射线重叠区内峰下的计数常具有能够提供重要信息的可能,但有时因这种重叠能区难于解谱而被摒弃。能量依赖的探测效率会使X射线峰出现左右不对称。探测器对X及γ射线响应形状的准确描述,及将已知信息在拟合中作... 详细信息

尽管多道能谱中X射线与γ射线重叠区内峰下的计数常具有能够提供重要信息的可能,但有时因这种重叠能区难于解谱而被摒弃。能量依赖的探测效率会使X射线峰出现左右不对称。探测器对X及γ射线响应形状的准确描述,及将已知信息在拟合中作为约束项的应用是精确分解出多道能谱中重叠区各成份计数的保障。充分利用Roo Fit软件包,建议了一种X射线峰形描述方式:利用洛伦兹函数描述其本征形状并与探测效率相乘,之后与分辨函数卷积以描述探测后的形状。测试显示放入与拟合出的峰下计数在统计误差范围内一致。所建议的方法及提供的代码可作为X及γ射线重峰区的解谱参考。

关键词：解谱拟合多道能谱

Dark matter direct search sensitivity of the PandaX-4T experiment

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2019年第3期62卷 49-57页

作者： HongGuang Zhang Abdusalam Abdukerim Wei Chen Xun Chen YunHua Chen XiangYi Cui BinBin Dong DeQing Fang ChangBo Fu Karl Giboni Franco Giuliani LinHui Gu XuYuan Guo ZhiFan Guo Ke Han ChangDa He ShengMing He Di Huang XingTao Huang Zhou Huang Peng Ji XiangDong Ji YongLin Ju ShaoLi Li Yao Li Heng Lin HuaXuan Liu JiangLai Liu YuGang Ma YaJun Mao KaiXiang Ni JinHua Ning XiangXiang Ren Fang Shi AnDi Tan AnQing wang Cheng wang HongWei wang Meng wang QiuHong wang siguang wang XiuLi wang XuMing wang Zhou wang MengMeng Wu ShiYong Wu JingKai Xia MengJiao Xiao PengWei Xie BinBin Yan JiJun Yang Yong Yang ChunXu Yu JuMin Yuan JianFeng Yue Dan Zhang Tao Zhang Li Zhao QiBin Zheng JiFang Zhou Ning Zhou XiaoPeng Zhou Shanghai Key Laboratory for Particle Physics and Cosmology Institute of Nuclear and Particle Physics (INPC) (INPC) and School of Physics and AstronomyShanghai Jiao Tong University School of Physics and Technology Xinjiang University Shanghai Key Laboratory for Particle Physics and Cosmology Institute of Nuclear and Particle Physics (INPC) and School of Physics and AstronomyShanghai Jiao Tong University Yalong River Hydropower Development Company Ltd. Shanghai Institute of Applied Physics Chinese Academy of Sciences School of Mechanical Engineering Shanghai Jiao Tong University School of Physics and Key Laboratory of Particle Physics and Particle Irradiation(MOE)(MOE) Shandong University School of Physics Nankai University Tsung-Dao Lee Institute School of Physics Peking University Department of Physics University of Maryland College Park School of Physics and Key Laboratory of Particle Physics and Particle Irradiation(MOE) Shandong University Center of High Energy Physics Peking University School of Medical Instrument and Food Engineering University of Shanghai for Science and Technology

The Panda X-4T experiment, a 4-ton scale dark matter direct detection experiment, is being planned at the China Jinping Underground Laboratory. In this paper we present a simulation study of the expected background in this experiment. In a 2.8-ton fiducial mass and the signal region between 1-10 keV electron equivalent energy, the total electron recoil background is found to be 4.9 × 10^(-5) kg^(-1) d^(-1) keV^(-1). The nuclear recoil background in the same region is 2.8 × 10^(-7) kg^(-1) d^(-1) keV^(-1). With an exposure of 5.6 ton-years, the sensitivity of Panda X-4 T could reach a minimum spin-independent dark matter-nucleon cross section of 6 × 10^(-48) cm^2 at a dark matter mass of 40 Ge V/c^2.

关键词： dark matter WIMPs direct detection xenon

An improved evaluation of the neutron background in the PandaX-Ⅱ experiment

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2020年第3期63卷 54-63页

作者： QiuHong wang Abdusalam Abdukerim Wei Chen Xun Chen YunHua Chen XiangYi Cui YingJie Fan DeQing Fang ChangBo Fu LiSheng Geng Karl Giboni Franco Giuliani LinHui Gu XuYuan Guo Ke Han ChangDa He Di Huang Yan Huang YanLin Huang Zhou Huang Peng Ji XiangDong Ji YongLin Ju YiHui Lai Kun Liang HuaXuan Liu JiangLai Liu WenBo Ma YuGang Ma YaJun Mao Yue Meng Parinya Namwongsa KaiXiang Ni JinHua Ning XuYang Ning XiangXiang Ren ChangSong Shang Lin Si AnDi Tan AnQing wang HongWei wang Meng wang siguang wang XiuLi wang Zhou wang MengMeng Wu ShiYong Wu JingKai Xia MengJiao Xiao PengWei Xie BinBin Yan JiJun Yang Yong Yang ChunXu Yu Jumin Yuan Dan Zhang HongGuang Zhang Tao Zhang Li Zhao QiBin Zheng JiFang Zhou Ning Zhou XiaoPeng Zhou Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China INPAC and School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai Laboratory for Particle Physics and CosmologyShanghai 200240China Yalong River Hydropower Development Company Ltd.Chengdu 610051China School of Physics Nankai UniversityTianjin 300071China School of Physics&International Research Center for Nuclei and Particles in the Cosmos&Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beihang UniversityBeijing 100191China School of Medical Instrument and Food Engineering University of Shanghai for Science and TechnologyShanghai 200093China Tsung-Dao Lee Institute Shanghai 200240China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Physics Peking UniversityBeijing 100871China Department of Physics University of MarylandCollege ParkMaryland 20742USA School of Physics and Key Laboratory of Particle Physics and Particle Irradiation(MOE) Shandong UniversityJinan 250100China Center of High Energy Physics Peking UniversityBeijing 100871China University of Chinese Academy of Sciences Beijing 100049China

In dark matter direct detection experiments,neutron is a serious source of background,which can mimic the dark matter-nucleus scattering *** this paper,we present an improved evaluation of the neutron background in the PandaX-II dark matter experiment by a novel *** of fully relying on the Monte Carlo simulation,the overall neutron background is determined from the neutron-induced high energy signals in the *** addition,the probability of producing a dark-matter-like background per neutron is evaluated with a complete Monte Carlo generator,where the correlated emission of neutron(s)andγ(s)in the(α,n)reactions and spontaneous fissions is taken into *** this method,the neutron backgrounds in the Run 9(26-ton-day)and Run 10(28-ton-day)data sets of PandaX-II are estimated to be(0.66±0.24)and(0.47±0.25)events,respectively.

关键词： dark matter direct detection xenon neutron background high energy gamma neutron generator

利用Geant4模拟研究中子在半导体中引发的单粒子翻转效应

在线全文

学校读者我要写书评

暂无评论

核技术 2015年第12期38卷 51-55页

作者：张欢王思广陈伟杨善潮北京大学物理学院核物理与核技术国家重点实验室北京100871 西北核技术研究所西安710024

静态随机存储器在反应堆中子辐射环境中会发生单粒子翻转(Single event upset,SEU)。钨和铜等重金属作为局部互联,在半导体中已得到广泛应用,这些重金属对中子在半导体中的单粒子翻转截面会产生影响。不同条件下单粒子翻转截面与临界能... 详细信息

静态随机存储器在反应堆中子辐射环境中会发生单粒子翻转(Single event upset,SEU)。钨和铜等重金属作为局部互联,在半导体中已得到广泛应用,这些重金属对中子在半导体中的单粒子翻转截面会产生影响。不同条件下单粒子翻转截面与临界能量的关系可作为器件设计和使用时的参考,利用Geant4对特定中子能谱在CMOS(Complementary metal oxide semiconductor)器件中的能量沉积进行模拟,给出特定能谱下翻转截面σ与临界能量Ec的关系:σ=exp[-18.7×Ec-32.3],其中能量单位为Me V,截面单位为cm2。并且模拟了1-14 Me V的单能中子在含有互联金属钨及不含钨的CMOS中的沉积能量及单粒子翻转截面,得出在1-14 Me V内单粒子翻转截面随中子能量而增大,且钨的存在会增加α粒子的产额,从而增大了1-3 Me V中子的单粒子翻转截面,而对4-14 Me V中子基本不会产生影响。

关键词：单粒子翻转反应堆中子重金属 Geant4

Constraining self-interacting dark matter with the full dataset of PandaX-II

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2021年第11期64卷 2-7页

作者： Jijun Yang Abdusalam Abdukerim Wei Chen Xun Chen Yunhua Chen Chen Cheng Xiangyi Cui Yingjie Fan Deqing Fang Changbo Fu Mengting Fu Lisheng Geng Karl Giboni Linhui Gu Xuyuan Guo Ke Han Changda He Shengming He Di Huang Yan Huang Ran Huo Yanlin Huang Zhou Huang Xiangdong Ji Yonglin Ju Shuaijie Li Qing Lin Huaxuan Liu Jianglai Liu Xiaoying Lu Wenbo Ma Yugang Ma Yajun Mao Yue Meng Nasir Shaheed Kaixiang Ni Jinhua Ning Xuyang Ning Xiangxiang Ren Changsong Shang Guofang Shen Lin Si Andi Tan Anqing wang Hongwei wang Meng wang QiuHong wang siguang wang Wei wang Xiuli wang Zhou wang Mengmeng Wu Shiyong Wu Weihao Wu Jingkai Xia Mengjiao Xiao Xiang Xiao Pengwei Xie Binbin Yan Yong Yang Chunxu Yu Hai-Bo Yu Jumin Yuan Ying Yuan Xinning Zeng Dan Zhang Tao Zhang Li Zhao Qibin Zheng Jifang Zhou Ning Zhou Xiaopeng Zhou School of Physics and Astronomy Shanghai Jiao Tong UniversityMOE Key Laboratory for Particle Astrophysics and CosmologyShanghai Key Laboratory for Particle Physics and CosmologyShanghai 200240China Shanghai Jiao Tong University Sichuan Research Institude Chengdu 610213China Yalong River Hydropower Development Company Ltd.Chengdu 610051China School of Physics Sun Yat-sen UniversityGaungzhou 510275China Tsung-Dao Lee Institute Shanghai 200240China School of Physics Nankai UniversityTianjin 300071China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China School of Physics Peking UniversityBeijing 100871China School of Physics Beihang UniversityBeijing 100191China International Research Center for Nuclei and Particles in the Cosmos&Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beihang UniversityBeijing 100191China Shandong Institute of Advanced Technology Jinan 250103China School of Medical Instrument and Food Engineering University of Shanghai for Science and TechnologyShanghai 200093China Department of Physics University of MarylandCollege ParkMaryland 20742USA School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China Key Laboratory of Particle Physics and Particle Irradiation of Ministry of Education Shandong UniversityJinan 250100China Research Center for Particle Science and Technology Institute of Frontier and Interdisciplinary ScienceShandong UniversityQingdao 266237China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Department of Physics and Astronomy University of CaliforniaRiversideCalifornia 92507USA Center of High Energy Physics Peking UniversityBeijing 100871China

Self-interacting dark matter(SIDM)is a leading candidate proposed to solve discrepancies between predictions of the prevailing cold dark matter theory and observations of *** SIDM models predict the existence of a light force carrier that mediates strong dark matter *** the mediator couples to the standard model particles,it could produce characteristic signals in dark matter direct detection *** report searches for signals of SIDM models with a light mediator using the full dataset of the PandaX-II experiment,basing on a total exposure of 132 *** significant excess over background is found,and our likelihood analysis leads to a strong upper limit on the dark matter-nucleon coupling *** further combine the PandaX-II constraints and those from observations of the light element abundances in the early universe,and show that direct detection and cosmological probes can provide complementary constraints on dark matter models with a light mediator.

关键词： dark matter direct detection self-interacting dark matter