Laser-induced breakdown spectroscopy (LIBS) is a new technology for testing and analyzing the composition and content of elements in materials.

This study aim to determine the content and distribution of hydrogen isotopes in hydrogen storage materials by using LIBS quantitative analysis technology.

Through independent design, construction and integration, a LIBS system was established for in-situ measurement of hydrogen isotopes in a vacuum chamber. Titanium sheets were used to prepare titanium-hydrogen samples with different concentrations of hydrogen and deuterium atoms to investigate the content and distribution of hydrogen isotopes in titanium using LIBS technology. The plasma parameters were calculated from the emission spectrum of titanium, and quantitative analysis on the content of hydrogen and deuterium atoms in the titanium sheet was carried out. Finally, the internal calibration method was employed to draw the calibration curves of hydrogen and deuterium, respectively, so as to determine the accuracy of this technology.

The plasma temperature calculated from the Boltzmann diagram is (16 000±1 000) K. Test results show that the linearity of calibration curves is increased by 4% by integrated intensity calibration, and the error of hydrogen isotope quantitative analysis is reduced by 2.8%. Based on the fitted curve, the concentration is consistent with the concentration determined by the pressure drop method during the sample preparation process. The average measurement error of hydrogen and deuterium is 3.19% and 1.94% respectively.

Provided that the plasma state conforms to the local thermal equilibrium and the plasma temperature of different elements is consistent, LIBS quantitative analysis can accurately measure the contents of hydrogen isotopes by using the internal standard method. Signal enhancement effect and data accuracy of LIBS meet the requirements of quantitative analysis.