Resonance absorption spectroscopy for laser-ablated lanthanide atom, 2; Expansion dynamics of laser ablation on cerium oxide (Contract research)

Miyabe, Masabumi   ; Oba, Masaki ; Iimura, Hideki  ; Akaoka, Katsuaki ; Maruyama, Yoichiro; Wakaida, Ikuo  

We have investigated propagation characteristics of the laser ablation plume produced from CeO sample to optimize experimental conditions for isotope analysis for low-decontaminated TRU fuel. Vertical flow velocity and horizontal expansion velocity of the plume were evaluated with optical TOF measurement and Doppler splitting measurement. These measurements revealed that (1) the ionic plume in vacuum consists of two components having vertical velocities of 4.7 km/s and 9.3 km/s whereas the atomic plume has a single component having velocity of 3.5 km/s, and (2) these velocities for particles in various excited states are almost the same, (3) horizontal velocity is about 20% slower than the vertical one, (4) plume expansion in gas environment is described with a drag model, (5) under an optimum condition for isotope analysis, plume expansion is almost stopped and an ionization degree is significantly decreased.