A comprehensive study of H emission in a TEA CO2 laser-induced helium gas plasma for highly sensitive analysis of hydrogen in metal samples

作者：Lie Zener Sukra^*; Khumaeni Ali; Niki Hideaki; Kurihara Kazuyoshi; Kurniawan Koo Hendrik; Hedwig Rinda; Fukumoto Ken ichi; Kagawa Kiichiro; Lee Yong Inn

来源：Journal of the Korean Physical Society, 2012, 61(1): 49-54.

DOI：10.3938/jkps.61.49

• Hydrogen analysis
• Excitation through helium metastable
• Selective detection of H
• LIBS
• TEA CO2 laser
• Laser-induced gas plasma
• Zircaloy sample
• Hydrogen analysis in film

Our previous work on an innovative method of hydrogen (H) analysis using the specific characteristics of a TEA CO2 laser, %26quot;selective detection method of H%26quot;, has been improved to realize a high H sensitive analysis with a detection limit of several A mu g/g. For this purpose, first, we clarified the origin of the H emission disturbance coming from H2O molecules; namely, we showed that most of the H emission came from H2O on the metal surface and not from H2O existing in the surrounding gas when we formed a laser-induced gas plasma. Second, the difference in the emission characteristics between the H emission from H2O on the metal surface and H emission from inside in sample was studied to determine the optimum gating time of the optical multi-channel analyzer (OMA). Third, the gas plasma was totally covered by fresh helium gas using a big pipe (5 mm in diameter) and by flowing a high amount of He (10 l/min). Also, we demonstrated that our methods could potentially be applied to H analysis in steel samples, where an H analysis with a sensitivity of less than 1 A mu g/g is required without employing a heating process, by removing H2O on the sample surface with the aid of defocused TEA CO2 laser irradiation. Thus, we stress that our method can be used for a highly sensitive, in-situ analysis of H for metal samples.

• 出版日期2012-7