A New Approach to the Theory of X‐ray Spectra of Metals with Allowance for the Finite Lifetime of the Deep Hole

The effect is analyzed of the deep hole forming on the inner level during X‐ray transition on the form of the corresponding emission and X‐ray photoelectron spectra of metals. The intensity of both the types of spectra is calculated in one common approach within the framework of the theory of scattering of the exciting photon on the electronic metal system. A generalization of the Wigner‐Weisskopf theory of radiation damping of excited atomic state is proposed for the case of a many‐particle system. The new approach permits to make allowance for the effect of the process of readjustment of valence electrons on the rate of radiation decay. It is shown that these phenomena can be taken into account formally if an effective non‐Hermitean Hamiltonian of a definite type is introduced into the theory. The general formulae obtained permit comparison of the results of different approaches in the theory of the spectra under investigation. The spectra can be analyzed numerically not only near the excitation threshold but also over the whole energy interval on the basis of simple models.