The Thermal Accommodation of Helium and Argon on Tungsten and Platinum at Elevated Temperatures

摘要

The thermal accommodation coefficients of helium and argon were measured on tungsten at temperatures of 800 to 1512 C under conditions which are considered to give a clean tungsten surface after flashing to 2400 C. Measurements of the accommodation of the same gases and of nitrogen have also been made on platinum at temperatures of 910 to 1320 C. An accommodation coefficient of 0.018 for helium on tungsten and of 0.24 for argon, both constant over the temperature range studied, was found. On platinum these gases and also nitrogen had constant accommodation coefficients over the range studied, the values being 0.026, 0.38 and 0.34 for helium, argon and nitrogen respectively. The values for helium on tungsten have been compared with those obtained by other workers at temperatures of 170 to 58 C and reasonable agreement has been found. It is concluded that the thermal accommodation of helium on tungsten is independent of temperature up to 1512 C. (Author)