共查询到16条相似文献,搜索用时 46 毫秒
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为精确测量142La的衰变数据,需制备出高活度、高丰度、无载体的142La样品。为去除或降低混合裂片中放射性镧的其他同位素,依据母子体衰变关系和同一质量链上独立产额的差异,提出了“三步分离”的分离模式。以一次BaCl2•2H2O沉淀、两次HDEHP萃取色层分离为手段建立了快速分离142La的化学流程,并研制了批式快速化学分离装置。流程耗时约20 min,化学回收率约80%,对其他核素的去污因数大于103,产品中142La与141La活度比大于3.5。 相似文献
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为了提高对核燃料微裂变过程诊断的灵敏度,要求使用短寿命裂变产物核素。142La就是适合的核素之一。但其现有衰变数据的准确度较差,需要对它进行更精确的测量。要获得准确的数据必须制备出纯的核素。 裂变产物是一个很复杂的体系,选择适当的辐照、冷却、分离、测量时间可以把干扰同位素的含量降低甚至消除,达到部分同位素分离的目的。 影响142La测量的主要同位素有141La和143La。其中,142La母体142Ba的半衰期(T1/2=10.6 min)远大于143La母体143Ba的半衰期(T1/2=14.7s)。235U经中于辐照后,冷却 3~5 min,143Ba全部 相似文献
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XU Yan-Bing XIAO Yong-Hou YANG Wei-Fan YUAN Shuang-Gui HE Jian-Jun XIONG Bing MA Tao-Tao 《核技术(英文版)》2001,12(4)
1 INTRODUCTIONIt has been rePorted[1l that the new neutron-rich isotoPe 237Th was produced via'"U(n,2P):"Th reaction by 14MeV/u neutron irradiations of natural uxedum and thehdelife of:3vTh has been given. Some experimental results reveal that in multi-nucleontransfer reaction (MNTR), neutron-rich projectile, neutron-rich taxget and reasonablyhigher incident energy favor the production of a heavy neutron-rich nuclei. In addition,dissiPative fragmntation of heavy taxget in the interme… 相似文献
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基于我国自主研制的核反应理论计算程序MEND G,针对200 MeV能量范围内光子诱发142~146,148,150Nd的核反应数据开展了系统的理论计算研究。首先分析了现有的多种光核反应测量数据,筛选出以实验数据作为理论计算依据;利用8种经典的光子强度函数模型和准氘模型,描述光子吸收截面;在此基础上,采用MEND G程序对142~146,148,150Nd开展光核反应理论计算,并通过优化6个Gilbert Cameron能级密度参数,得到适用于Nd天然稳定同位素的普适能级密度,同时针对142,143Nd得到与实验结果符合更好的定域能级密度参数。通过对分光中子出射截面的系统分析,建立了ENDF 6格式的光核反应数据。结果表明,推荐的光核数据合理,与实验测量数据一致性较好,该数据已收录在CENDL 32光核子库中。 相似文献
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YANG Zhihong DING Youqian ZHANG Shengdong YANG Lei SUN Hongqing MA Peng 《原子能科学技术》1959,54(10):1737-1744
To determine the half-life of gaseous fission product 88Kr accurately, three purified 88Kr sources were prepared from irradiated uranium targets by using a radiochemical separation process. With 85Kr as the internal monitor, 137Cs/57Co as the external label sources, both single detector position relay method and double detectors position relay method were applied to track the characteristic 196.3 keV gamma rays by multiple high purity germanium detectors covering more than eight times half-lives. The results from three separate determinations were discussed, and a half-life of (2.796±0.015) h for 88Kr was presented. 相似文献
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LUO Xiao-Bing ZHANG Ruan-Yu CHEN Shi-Guo LI Tai-Hua AN Zhu CAO Yang-Shu 《核技术(英文版)》2005,16(6):338-340
A 13.4 MeV deuteron beam from the 1.2 meter cyclotron of Sichuan University was used to determine the protein content in wheat seeds on the basis of (d,p) reactions. The influence of the variation of the water content in seeds has been investigated. 相似文献