THERMAL RELEASE OF INERT GASES FROM (110) AND (211) TUNGSTEN SURFACES

Clean (211) and (110) surfaces of tungsten have been bombarded with inert-gas-ion beams in the energy range 40 eV-5 keV. Thermal desorption spectra of the trapped gas show patterns of peaks characteristic of the ion and the face bombarded. The results are comparable to those obtained previously for a (100) tungsten surface. In particular, all peaks below 1650°K are associated with desorption from sites within about 10 Å of the crystal surfaces, while the single peak above 1700°K is the result of isotropic diffusion of ions which have penetrated more than 10Å. Evidence is presented to support the hypothesis that the trapping sites consist of substitutional gas atoms and associated point defects. © 1969 The American Institute of Physics.