共查询到20条相似文献,搜索用时 125 毫秒
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To monitor the integral dose deposited in the BESⅢ electromagnetic calorimeter whose perfor-mance degrades due to exposure to the BEPCⅡ background, a 400 nm IMPL RadFET dosimeter-based integral dose online monitor system is built. After calibration with the 60Co source and verification with TLD in the pulse radiation fields, an experiment was arranged to measure the BEPC Ⅱ background online. The results are presented. 相似文献
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YAN Liang HE Kang-Lin LI Wei-Guo BIAN Jian-Ming FU Cheng-Dong HUANG Bin LIU Ying L Qi-Wen NING Fei-Peng SUN Sheng-Sen XU Min ZHANG Jian-Yong ZHU Yong-Sheng 《中国物理C(英文版)》2010,34(2)
In this paper,the kinematic fitting with the Lagrange multiplier method has been studied for BESⅢ experiment.First we introduce the Lagrange multiplier method and implement kinematic constraints.Then we present the performance of the kinematic fitting algorithm.With the kinematic fitting,we can improve the resolution of track parameters and reduce the background. 相似文献
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研究表明,岩石在加载过程中表面的红外辐射随应力发展而变化,而辐射信息的有效提取与辐射背景存在密切关系。通过理论分析不同实验环境对岩石受力热红外光谱变化影响,开展了花岗岩在室内外环境下的受力热红外光谱观测实验,分析了不同辐射背景下岩石红外辐射与应力的相关性以及由应力引发的辐射变化信息的强弱差异,并对两种环境下岩石应力热红外探测的优势波段进行了对比分析。结果表明,辐射背景对岩石受力热红外光谱探测结果有重要影响,室外环境因背景辐射较弱,相同应力作用下的红外辐射变化更加显著,与应力之间的相关程度更高,优势波段区间更宽,更加有利于岩石应力的热红外探测。8.0~11.8 μm波段是利用热红外遥感监测地表花岗岩应力变化的优势波段。 相似文献
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研究了不同响应波长的HgCdTe器件在不同背景辐射条件下的噪声变化.随着背景辐射的增加,甚长波器件的噪声减小,而中波器件相反.噪声频谱测量表明,产生-复合噪声分量和1/f噪声分量是器件的主要噪声来源,并且这两个分量随背景的变化趋势相同.非平衡载流子和器件有效寿命的理论分析,表明器件噪声随背景辐射的变化存在一个极大值,而中波和甚长波器件处在不同的作用区域内,接受到的背景辐射对载流子浓度和器件有效寿命的影响不同,从而噪声变化表现不同.在此基础上,提出了"临界背景通量密度"的概念. 相似文献
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Sajad Borzoueisileh Bruno Comby Meysam Khosravifarsani Parya Roshan Shomal Mir Saeid Ramezani 《Isotopes in environmental and health studies》2014,50(1):114-119
Although the average effective human dose from natural background radiation is about 2.4 mSv per year, the students of the Saeid Nafisi school in Ramsar received effective doses of about 250 mSv while studying there for over 5 years. The goal of this project was a retrospective study of the health status of former students of this school and their offspring. The list of the students of the Saeid Nafisi school (high background radiation) and Taleghani and Kashani schools (ordinary background radiation) was provided by the Department of Education. After matching sex, age and socioeconomic level and obtaining their consent, part 1 of the specifically designed questionnaire was filled out by interview, and clinical examinations were recorded in part 2 of the questionnaire by a physician. The data were analysed using Statistical Package for the Social Sciences 16. Our study shows that 88.1 % of general examinations of high background radiation school students were normal as compared with 85.7 % for control group. There were no significant differences. This study is interesting and unique. It reveals that there is no health emergency related to these high radiation doses. We recommend continuing the health supervision of this population in the future. 相似文献
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YAN Liang HE Kang-Lin LI Wei-Guo BIAN Jian-Ming FU Cheng-Dong HUANG Bin LIU Ying NING Fei-Peng SUN Sheng-Sen XU Min ZHANG Jian-Yong ZHU Yong-Sheng 《中国物理C(英文版)》2010,34(2):204-209
In this paper, the kinematic fitting with the Lagrange multiplier method has been studied for BESⅢ experiment. First we introduce the Lagrange multiplier method and implement kinematic constraints. Then we present the performance of the kinematic fitting algorithm. With the kinematic fitting, we can improve the resolution of track parameters and reduce the background. 相似文献
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The earth background radiation is a kind of main background interference for satellite borne laser warning system in the space environment, and it is so necessary that the radiation characteristic be studied. In this paper, the mathematic model of the earth background radiation is established, the input parameters of 6S model are analyzed and set, and the simulation of earth background radiation is carried on aiming at the alarm wavelength 1.315 μm and the waveband 0.9-1.7 μm which is the responsive bandwidth of the detector. The results show that: with the increase of zenith angle, the irradiance from ground reflection increases, but the irradiances of atmospheric path radiation and surface-atmosphere interaction at the satellite level decrease; comparing with other two parts, the irradiance from ground reflection weighs most, and the corresponding percentages for 1.315 μm and 0.9-1.7 μm are 75.89% and 73.99%, respectively. The total irradiance at the satellite level from earth background radiation has exceeded the detection sensitivity of the system (about 1 mW/cm2), which may arouse the false alarm. So, the special technique of background suppression must be studied. 相似文献
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A. G. Beda V. B. Brudanin E. V. Demidova V. G. Egorov M. G. Gavrilov V. N. Kornoukhov A. S. Starostin C. Vylov 《Physics of Atomic Nuclei》2004,67(11):1948-1952
The investigation of the background structure of the spectrometer GEMMA was carried out in a low-background laboratory in ITEP. GEMMA is destined for measurement of the neutrino magnetic moment near the core of a nuclear power plant (NPP) reactor. The results of the investigation in ITEP and measurement of the background in the experimental hall at the Kalininskaya NPP proved that GEMMA is ready for the start of the experiment at the reactor. Now the preparation of the experimental hall for the measurement is completed and an assembling of the setup is in progress. 相似文献
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HE Miao WANG Yi-Fang BIAN Jian-Ming CAO Guo-Fu DENG Zi-Yan HE Kang-Lin HUANG Bin JI Xiao-Bin LI Gang LI Hai-Bo LI Wei-Dong LIU Chun-Xiu LIU Huai-Min MA Qiu-Mei MA Xiang MAO Ya-Jun MAO Ze-Pu MO Xiao-Hu QIU Jin-Fa SUN Sheng-Sen SUN Yong-Zhao WANG Ji-Ke WANG Liang-Liang WEN Shuo-Pin WU Ling-Hui XIE Yu-Guang YANG Ming YOU Zheng-Yun YU Guo-Wei YUAN Chang-Zheng YUAN Ye ZANG Shi-Lei ZHANG Chang-Chun ZHANG Jian-Yong ZHANG Ling ZHANG Xue-Yao ZHANG Yao ZHENG Zhi-Peng ZHU Yong-Sheng ZOU Jia-Heng 《中国物理C(英文版)》2008,32(4)
Material effect of inner-detectors on the performances of the BESⅢ Electromagnetic Calorimeter (EMC)is investigated.The BESⅢ Time-Of-Flight counters(TOF)have been utilized to improve the energy resolution and detection efficiency for photons after a careful energy calibration.A matching algorithm between TOF and EMC energy deposits is developed,and the effects of beam-related background are discussed.The energy resolution is improved and the photon detection efficiency can be increased by the combined measurement of EMC and TOF detectors. 相似文献
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欧洲核子中心的大型强子对撞机探测器预计工作在 1 0 34 /(cm2·s)亮度 ,这将导致实验大厅的本底非常严重 .薄气隙室将作为 ATLAS实验中的前端 μ子触发器 .按照模拟计算 ,实验大厅薄气隙室周围的主要本底是中子和光子 .报告了薄气隙室探测器的 γ灵敏度的实验测量 .使用 γ能量从20ke V到1.8Me V的放射性 γ源 .目前测量的灵敏度小于 1 % ,与用 EGS4模拟计算结果相吻合. The Large Hadron Collider (LHC) at the European Laboratory for Particle Physics (CERN) is expected to operate at the luminosity of 10 34 /(cm 2 ·s), and the resulting background condition in the experimental hall would be quit severe. Thin Gap Chamber (TGC) will be used for forward muon triggering in the ATLAS experiment. According to a simulation, the main source of the background around TGC in the experimental hall is neutrons and photons. The sensitivity measurement for TGC... 相似文献