2022 年 30 巻 2 号 p. 65-70
The alumina reduction method using laser ablation has been developed for recent several years. In this study, translational temperature and column density measurements of laser ablation plasma generated by nanosecond pulsed laser were conducted. Laser absorption spectroscopy using Al I 394.401 nm was performed at the pressure of 10 Pa and the translational temperature and column density were determined by spectral fittings to the Gaussian function. These peak values at the height of 5 mm were 10,200 K and 1.5×1017 m-2, respectively. The column density decreased at a height farther than 8 mm because of recombination and this affects the alumina reduction efficiency directly, which suggests that the height of the collected plate should be adjusted according to the pressure to increase the collected mass of the ejected Al atoms.