Hydrogen and Deuterium Analysis Using Laser-Induced Plasma Spectroscopy

激光诱导等离子体光谱分析(LIPS)作为一种快速的定量分析工具，已经在许多领域得到了广泛的应用。然而，由于固体材料中的氢是普通的，所以很少有关于固体材料中杂质氢的分析工作的报道。在1atm条件下，氢发射(Hα)经历了严重的谱线展宽和发射效率的急剧下降。在这项研究中，我们证明了通过控制激光等离子体产生中的一些条件，如环境气体压力、气体种类和激光聚焦，可以实现H分析。作为氢分析的应用之一，我们对核电站工业中非常重要的问题--Zicaloy样品进行了氢分析。1)减压氢分析发现，氦在10Torr附近的低压为固体中的氢分析提供了良好的条件。本文对含氢200ppm~4300ppm的Zicaloy样品进行了高灵敏度和高精度的分析，采用了相当极端的离焦条件(f=200m透镜为-45 mm)，获得了良好的线性校准曲线，检出限约为50ppm。为此，激光脉冲被有意聚焦在样品表面以上10 mm处，以诱导气体击穿等离子体，在那里产生He原子，并从样品表面激光烧蚀。我们还证明了通过抑制H-α和D-α的光谱展宽，可以同时进行H和D的分析，但峰值波长漂移仅为0.18 nm。

Laser-induced plasma spectroscopy (LIPS) has been expanded in many fields as a rapid quantitative analytical tool. However, little work has been reported on the analysis of hydrogen as impurity in solid materials because ordinary. LIPS is conducted at 1 atm, under which condition hydrogen emission (Hα) undergoes a severe line broadening and drastic diminishing in emission efficiency. In this study we have demonstrated that H analysis can be realized by controlling some conditions in the laser plasma production, such as ambient gas pressure, gas kind and laser focusing. As one of the application of H analysis, we have made H analysis in Zicaloy sample, which is very important issue in the nuclear power station industry.1) H analysis at reduced pressureIt has been found that helium low pressure around 10 Torr offers a good condition for H analysis in solids. High sensitive and high precision analysis was demonstrated on zicaloy samples (containing H in the range from 200ppm and 4300ppm) by employing rather extreme defocusing condition (-45mm for f=200m lens) for YAG laser irradiation(140mJ), presenting a good linear calibration curve with a detection limit of about 50ppm.2)H analysis in He gas at 1 atmAnother excitation technique was developed; namely, excitation through He metastable-state(He*). For this purpose, YAG laser pulse was intentionally focused at 10mm above the sample surface so as to induce a gas breakdown plasma, where He*atoms are produced, together with the laser ablation from the sample surface. It was confirmed that a good linear calibration curve is available even in this case with a detection limit of around 100ppm.3) Deuterium analysisWe have also proved that H and D(deuterium) analysis can be made simultaneously by suppressing the spectra broadening of Hα and Dα., nevertheless the peak wavelength shift is only 0.18nm..