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A simulation method of charged particle scattering in a crystal lattice is described. Angular distributions of protons and positrons leaving the crystal are calculated and the orientational distributions of axial channeling particles are received. The influence of the experimental geometry and the crystal condition on the obtained results is discussed. It is shown that binary collision calculation gives agreement with experimental results. I n the present paper the first results of a computer simulation of the scattering of positrons in a single crystal are given. Since the applicability of the classical mechanics to the description of the channeling phenomena of light p-particles is under discussion, we choose a computer model allowing for the most exact simulation of the experimental conditions, without the usually applied methods of computing time minimization. I n our calculation the particle trajectory is observed from the first collision point until the particle leaves the certain geometrical dimension of the single crystal. The calculation thus yields the angular distributions of the particles leaving the single crystal in dependence on the rotation angle of the single crystal relative to the incident beam axis. The angular distributions are integrated over the detector aperture of the simulated experiment geometry and these values depending on the crystal rotation angle are compared with the experimental data.

Experiments on the swift electron transmission through single crystals showed orientation-dependent maxima of the Rutherford scattering yield, which were explained by a classical focusing effect of electrons on the atomic rows o r planes and subsequent large-angle scattering /1 to 3/. Further investigations proposed a new classical model of weavon and rosetton channeling /4, 5/. In the quantum theoretical treatment of the bound states of electrons with atomic rows o r planes attention was also paid to the investigation of anomalous transmission through a crystal /6 to 9/. In the present paper we discuss in the scope of the quantum theory of where 1, n a r e the azimuthal and radial quantum numbers, f = ( n + 111 + 1/2) ,

A detailed treatment in the classical and quantum-mechanical approximations of the bound motion of energetic electrons with (011) atomic planes of Si is given. For electrons with energies up to 2.5 MeV only a few resolved quantized states are obtained. The angular distributions of electrons in the ground and exited states are calculated and compared with experimental data. It is shown that electrons are effectively channeled through the crystal along the atomic planes, thereby being mainly in an excited state.npOBeAeH0 PaCCMOTpeHHe B HJIaCCHYeCKOM EI KBaHTOBO-MeXaHH9eCKOM IIPEI~JIH-XeHIIHX CBH3aHHOrO ABHXieHHR 6bICTPbIX 3JIeKTPOHOB OTHOCHTeJIbHO (011) aTOMHOB IIJIOCKOCTH Si KpmTanna. n p n 3~e p r m x BJI~HTPOHOB no 2,5 MeV p e a n m y~o~c s T o m K O HecHojIbKo p a 3 p e n r e~~~x COCTOHHIIB. PaccsmaHbi yrnome pacnpenene-HMB BJIBHTPOHOB B OCHOBHOM EI BO36yWAeHHOM COCTOHHHH, KOTOPbIe CpaBHHBaIoTCfl C 3KCIlePHMeHTaJIbHbIMH pe3yJIbTaTaMH. nOHa3aH0, 9 T O 3JIeHTPOHbI B@@eKTHBHO KaHaJIHpyIoT 9epe3 KpMCTaJIJIbI BAOJIb aTOMHOa IIJIOCKOCTM, HaXOEHCb IIpeEIMyWeCTBeHHO B B036YWHeHHOM COCTOHHEIH.