Laser-induced-vaporisation mass-spectrometry studies on UO2, UC, and ThO2

Partial pressures of different species present in the vapour phase over UO 2 , UC, and ThO 2 have been studied at very high temperatures (>3000 K), by transient heating of the sample with a 532 nm laser pulse of ∼8 ns duration with time-resolved mass-spectrometric detection. The surface temperature was varied by changing the laser incident power density on the sample. In the case of the UO 2 system, which has been studied extensively, these results serve for comparison; and in the case of UC they provide additional information. For the ThO 2 system, this study gives the first information for very high temperatures.