The thermal radiation processes in the Sc-H system

The thermal-radiation processes in the system Sc-H-2 have been investigated. The high-current 4 MeV electron accelerator LAE-5 has been used with a focused electron beam. As a result of experiments at different doses and dose rates (0.025-1.5 Mrad/s) in vacuum and in a hydrogen atmosphere, the main peculiarities of the thermal-radiation processes in Sc-H-2 have been obtained. It was shown that at irradiation of Sc in H-2 environ, the thermal-radiation synthesis (TRS) of Sc hydride, ScH1.92, occurred. It was established that on increase of irradiation dose, the temperature of the sample increases to 200-300 degreesC, after which a sharp temperature jump was observed. Actually, the reaction Sc+H-2 proceeded in a thermal explosion regime. It was shown that the characteristics of TRS depend essentially on irradiation dose rate. (C) 2003 Published by Elsevier B.V.