Theoretical Study of Ion Neutralization Process Near Silid Surfaces, Ⅱ －Range of the Process－

A one-electron model calculation of the ion neutralization process near bcc (100) surfaces has been made basing on the resonant tunneling model. It has been shown that the ion survival probability Ps, at an ion velocity v in the range of 0.4～3KeV often used in ISS converges very slowly as a function of number n of atoms or layers in the substrate : Even 11x11x11 atomic cluster model is still too small, etc. It has been shown that the charge fluctuation on the target atom produced by the electron exchange between the ion and the target atom propagates into the substrate more than a few tens of atomic spacings, and returning to near the collision point in the collision time, it affects the final value of the electron occupation number N00(T) on the ion, and so the neutralization probability. It has been estimated that the range of the neutralization process amounts to as much as 1OO atoms, indicating that the ion neutralization process near the solid surface is a wide range process. It has also been shown that the range or n is an increasing function of 1/v and of the band width or hopping integrals between atoms in the substrate