Evolution of a weak-distorted harmonic oscillator in an intensive homogeneous variable field

The method of constructing the operator of the time evolution of quantum system in the external variable field in the case when its hamiltonian is slightly ''distorted'' is developed. The decomposition of the evolution operator represents a direct analog of the successive theory of sudden perturbations. The process of the Coulomb excitation of the charged isotropic harmonic oscillator in far collisions with a multicharged random ion is considered. Separate channels of the oscillator excitation are studied in detail as well as energy losses on account of the Coulomb oscillator excitation (effective slowing-down of the multicharged ion and struggling). The results obtained are valid at any charged of an incident particle and any relative velocity