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 radiat ion passes through insert devices (filters, mirrors or monochromators) . The micro-processes are photoionization, Compton scattering, Rayleig h scattering, electron elastic and inelastic collisions, electron Brem sstrahlung scattering and the Auger process. The energy of x rays is c onverted into the electrons' kinetic energy and atomic excitation ener gy by photoionization and Compton scattering. High-energy photoelectro ns slow down mainly through inelastic collisions with the atoms in mat erials. The energy deposition in a material is simulated according to the x-ray atom interaction cross sections and photoelectron-atom colli sion cross sections. The results of a calculation for x rays traversin g Si and Be plates of 1.0 cm in thickness are presented and discussed as one typical example concerning important materials in optical devic es. 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 o f Physics.