同位素稀释质谱法测定空心玻璃微球内氘气总量

Measurement of Gas Gross in Hollow Glass Microsphere by Isotopic Dilution Mass Spectrometry

作为惯性约束核聚变(ICF)第一代靶丸,空心玻璃微球(HGM)内充燃料气体的组分、比例和密度均有严格要求,气体总量的测定至关重要。介绍了同位素稀释质谱法(IDMS)测定空心玻璃微球内氘气气体总量的分析方法。该方法采用氢气为稀释剂,活性炭作为吸附剂制备氘气和氢气的混合气体,用质谱计测定样品中氢同位素丰度。通过热力学公式推导、计算,求得HGM内氘气摩尔数。实验结果表明:用IDMS法测量HGM内痕量氘气总量切实可行,其测量下限为10-8 mol,测量结果的相对标准偏差小于5%(n=4或3,按照极差法计算),符合测量要求。

In inertial confinement fusion（ICF）, the hollow glass microsphere（HGM） is the first pellet, and the measurement of gas gross, constituent and density in HGM is very important. In this paper, the measurement methods of the D2 gross in HGM by isotopic dilu- tion mass spectrometry（IDMS） are described. The mixture of D2 and H2 was firstly prepared with H2 as the spike and active carbon as the adsorbent. Then the isotope abundance of the mixture was measured by mass spectrometer. And the mole number of D2 in HGM was calculated with the gas state of equation. The results show that the trace D2 can be measured by IDMS, and the lower measurement limit is 10^-8 mol. The relative standard deviation of the measurement is less than 5%（n=4 or 3, calculated by range method）, meeting the requirement.