Experimental Investigation of the Scattering of a Monoenergetic Argon Molecular Beam from a Solid Argon Surface

摘要

An aerodynamic molecular beam and phase sensitive detection system were used T(o) investigate the spatial distributions of argon atoms scattered from solid argon for: incident beam energies of 0.3 (To = 1400K), 0.37 (1700K), 0.43 (2000K), and 0.5 ev (2300K); incident angles (measured with respect to the surface normal) of 0 to 70 deg; and solid argon temperatures of 13.5K. The effect of surface temperature on the distributions for 0.5-ev beams at 70-deg incidence was studied in the range from 13.5 to 23K. Both in-plane and out-of-plane spatial distribution measurements were made, and highly nondiffuse supraspecular flux distributions were observed for the noncondensing atoms. The experimental data indicated that the angle of maximum reflected intensity was independent of the beam intensities, beam energies, beam incidence angles, and surface temperatures investigated; and its value was approximately 75 deg. The beam capture coefficient was a monotonically decreasing function as the angle of incidence and the incident beam energy increased. (Author)