Quantum Adsorption: A Critical Phenomemon.

The sticking coefficient alpha(E) describes the probability that an incoming charged particle with a low energy E will stick to the surface of the dielectric fluid. The quantum- mechanical prediction lim alpha(E) = 0 is found to hold to all orders in gamma, the coupling to the surface E->0 over excitations. When gamma exceeds a critical value gamma sub c , inelastic scattering destroys quantum interference and lim alpha(E) not= 0. For larger gamma a classical description is valid. Near gamma sub c we find E->0 over features reminiscent of critical phenomena in systems with continuous phase transitions.