Study of coherent bremsstrahlung and comparison with channeling radiation.

摘要

Theoretical calculations of channeling radiation and coherent bremsstrahlung and experimental measurements of channeling radiation are presented in this work.; The many-beam formalism and the standard Hartree-Fock potentials were used to calculate the channeling radiation transition energies. The widths of the spectral lines were determined by the use of the complex potential which describes the incoherent scattering from vibrating atoms of the crystal. A series of channeling radiation experiments were performed at the Darmstadt superconducting linear accelerator S-DALINAC using incident electron beam energies of 6.00, 9.00 and 10.18 MeV on a germanium crystal. The results of the theoretical calculations (planar case) were compared with experimental data and are in reasonable agreement with the observed results. The observed linewidths are somewhat larger than the calculated values and this disagreement is thought to be due to crystal heating and lattice defects. The channeling radiation energies scale as {dollar}gammasp{lcub}5/3{rcub}{dollar} ({dollar}gamma{dollar} is the ratio of the electron total energy and its rest mass) for the deeply bound states (states localized in the vicinity of the atomic plane) and {dollar}gammasp2{dollar} for states localized between the channeling planes. Multiple scattering and x-ray absorption in the crystal are found to modify the shapes of the channeling peaks and shift their centers. The dependence of the channeling states relative to the crystal thickness is determined and theoretical values of the occupation length are calculated for the 1-0 transition.; Theoretical calculations of coherent bremsstrahlung are also presented, and compared with channeling radiation.