[15p-2Q-1~17] 8.7 Plasma phenomena, emerging area of plasmas and their new applications

△ [15p-2Q-3] Analysis of the Time Evolution of Cavitation Bubbles Formedin Pulsed Laser Ablation Plasmas in supercritical CO₂

〇(DC)Hitoshi Muneoka^1,2, Shohei Himeno¹, Keiichiro Urabe^1,2,3, Sven Stauss¹, Kazuo Terashima¹ (1.Univ. Tokyo, 2.JSPS Research Fellow, 3.Air Liquide Lab.)

Keywords:Laser Ablation,Supercritical fluid (SCF),Shadowgraph imaging

The time evolution of cavitation bubbles formed in pulsed laser ablation plasmas in supercritical CO₂ were investigated by shadowgraph imaging and numerical simulations. It was divided into three phases near the critical point: Expansion, Double layer formation, and Contraction. The distribution of the direction of the refracted light in the shockwave in the expansion phase, the diffuse interface of the inner bubble in the double layer phase, and the time evolution of the size of the bubble in the contraction phase are discussed in this paper. The results imply that the properties and fluid structure peculiar to SCF affect the structure of cavitation bubbles.