钨中氢同位素热脱附实验的速率理论模拟研究  

Simulation of the experiments on thermal desorption spectroscopy of hydrogen isotope in tungsten with the framework of rate theory

作　　者：邹达人[1] 金硕[1] 许珂[1] 吕广宏[1] 赵振华[1] 程龙[1] 袁悦[1] 

机构地区：[1]北京航空航天大学,物理科学与核能工程学院,北京100191

出　　处：《物理学报》2015年第7期193-199,共7页Acta Physica Sinica

基　　金：科技部国际热核聚变实验堆(ITER)计划专项(批准号:2013GB109002);教育部博士点基金(批准号:20111102110038);国家教育部回国人员科研启动基金资助的课题~~

摘　　要：本文采用基于速率理论的模拟方法研究钨材料中氢同位素氘的热脱附谱.热脱附数据来源于520 K下受等离子体辐照的多晶钨,入射离子能量为40 eV,剂量为1×1026D/m2.通过调节速率理论中的俘获能、俘获率等参数,最终获得与实验相符合的热脱附拟合谱.拟合结果表明,钨中俘获的氘存在于三种俘获态,俘获能分别为1.14 eV,1.40 eV和1.70 eV,相应脱附温度峰值为500 K,600 K和730 K.这三个俘获能分别应对应于第一原理计算得到的空位俘获第3—5个氢原子的俘获能(含零点振动能修正)、空位俘获第1—2个氢原子的俘获能,空位团簇对氢原子的俘获能.模拟结果表明,在本辐照实验条件下,钨中空位及空位团簇是氘在钨中的主要俘获态.Simulation of thermal desorption spectroscopy（TDS） of the hydrogen isotope-deuterium in tungsten has been investigated in this paper based on rate theory. Data are obtained using polycrystalline tungsten, which is under the irradiation of a plasma with an energy of 40 eV and a dose of 1× 10^26 D/m^2 at 520 K. By adjusting the trapping energy,trapping rate, and other parameters in the rate theory, we can obtain the TDS simulation spectrum, which coincides with the experimental results. It is found that there mainly exist three trapping states for deuterium in tungsten, whose trapping energies are 1.14, 1.40 and 1.70 eV, and the temperature peaks of them is 500, 600 and 730 K, respectively.These three trapping energies correspond to the energy for trapping the 3rd-5th hydrogen by vacancy（the zero point energy correction has been taken into account）, the energy for trapping the 1st-2nd hydrogen by vacancy, and the energy for trapping the hydrogen by vacancy cluster, obtained from first-principle calculation, respectively. It is suggested that the vacancy and vacancy cluster are the main trapping objects for deuterium in tungsten, under the experimental condition mentioned above.

关 键 词：氢同位素 热脱附谱 速率理论 

分 类 号：O562[理学—原子与分子物理]