Diffraction of He and H2molecular beams from a low temperature metal surface

Abstract
Thermal atom diffraction from a densely packed metal surface has been observed for the first time, by using a supersonic beam and a low temperature Ag (111) crystal face. For He-Ag, the intensity of the (1,0) diffraction peak is about 2*10-3 times that of the specular beam, while for H2-Ag it is about 3*10-2 times that of the specular beam.