Experimental studies of the dynamics of nitrogen van der Waals cluster scattering from metal surfaces

摘要

Experimental measurements of the dynamics of the collisions between N2van der Waals clusters and metallic surfaces are discussed. Large N2van der Waals clusters are formed by high pressure nozzle expansions of pure N2and N2seeded in helium. Angular distributions and rotational energy distributions of the fragments of these clusters resulting from impact with well characterized silver and iron surfaces were obtained using electron beam induced fluorescence. Angular distributions were characterized by tangent shifted scattering lobes, and rotational energies which are largest at the surface normal. The dependence of the angular distributions on N2fraction in the seeded beam, expansion backing pressure, and surface structure, composition, and temperatures were investigated.