The role of incoherent scattering in radiation processes at small angles of incidence of particles on crystallographic axes or planes

Abstract

The intensity of multiple scattering of e +- moving inside planes and tubes formed by atoms of a crystal is several orders of magnitude higher than in an amorphous material. It is shown that in spite of this, the Landau-Pomeranchuk effect (LPE) does not occur on incidence on crystallographic axes and planes at sufficiently small angles of high energy e +- and y. An expression is obtained for the probability of radiation of a y ray by e +- in a uniform field in the presence of uncorrelated multiple scattering of the e +- . It generalizes the xpression obtained by Migdal for description of the Landau-Pomeranchuk effect for the probability of emission of a y ray by e +- moving in an amorphous beam, and the Klepikov-Nikishov-Ritus expression for the probability of emission of a y ray by e +- moving in a uniform electromagnetic

field.