A quantitative analysis of hydrogen isotope retention in tokamak first wall materials by optical spectroscopy and mass-spectrometry

In this work, the applicability of laser-induced ablation for diagnostics of hydrogen isotope retention is demonstrated. The analysis of residual gases based on mass spectrometry and Penning discharge optical spectroscopy were used as methods for recording the deuterium flux. It is shown that the optical spectroscopy of the Penning discharge records a larger number of deuterium atoms than mass spectrometric analysis. The difference of the quantitative evaluation relates to the registration of D$_2$, H$_2$, HD molecules by mass spectrometer, while the Penning discharge optical spectroscopy shows the presence of protium and deuterium regardless of the chemical composition of the material.