HEAT-ENERGY DEPOSITION IN X-RAY INTERACTION WITH MATERIALS APPLICATION TO SI AND BE

Based on the analysis of the micro-processes due to the interaction of synchrotron radiation with materials, we have developed a theoretical method to calculate the heat energy deposited when synchrotron radiation passes through insert devices (filters, mirrors or monochromators). The micro-processes are photoionization, Compton scattering, Rayleigh scattering, electron elastic and inelastic collisions, electron Bremsstrahlung scattering and the Auger process. The energy of x rays is converted into the electrons' kinetic energy and atomic excitation energy by photoionization and Compton scattering. High-energy photoelectrons slow down mainly through inelastic collisions with the atoms in materials. The energy deposition in a material is simulated according to the x-ray atom interaction cross sections and photoelectron-atom collision cross sections. The results of a calculation for x rays traversing Si and Be plates of 1.0 cm in thickness are presented and discussed as one typical example concerning important materials in optical devices. The dependence of the energy deposition on the angle of incidence of the x rays is also discussed. Both the utility and validity of the present simulation method are discussed. (C) 1995 American Institute of Physics.