微量气样中氦同位素的质谱峰高比测定法

The Measurement of Mass Spectrometric Peak Height Ratio of Helium Isotope in Trace Sample

本文使用作者设计的气样净化装置和引进的 VG5400静态真空稀有气体质谱计,以制备的空气氦为标准样,对微量气态样品中氦同位素的峰高比测定法进行了实验研究.结果表明,天然气样经净化后其氮氖组分占99%,当质谱计内的氦量大于4×10^(-7)cm^3·STP·He 时,其灵敏度稳定,约为10^(-4)A/cm^3·STP·He,17天內的_εHe/~4He 值精度为1.32%.最后,具体讨论了氦同位素质谱峰高比测定法的“ABA”模式及其条件.

This paper discusses a experiment study on the measurement of massspectrometric peak height ratio of helium isotope in the trace gaseoussample by using the gas purification line designed by the authors andmodel VG—5400 static-vacuum noble gas mass spectrometer imported andair helium as a standard.The results show that the amount of He andNe in natural gas sample is 99% after purification.When the amount ofHe in Mass Spectrometer is more than 4×10^(-7)cm^3 STP,it's sensitivityremains stable,about 10^(-4)A/cm^3 STP He and the precision of ~3He/~4Heratio within the following 17 days is 1.32%.Last,we deal with the“ABA”pattern and experiment condition in the measurement of massspectrometric peak height ratio of He isotope.