Monte Carlo Codes to Study the Transport of X-Rays and Fluorescent Light in the Atmosphere.

摘要

A machine procedure,designated as AURORA,was developed for use in studies of the effects of non-local energy deposition by X-rays in the atmosphere. The AURORA procedure provides two optional methods of treating the slowing down in the atmosphere of the electrons produced by X-ray collisions. The first method assumes that the earth's magnetic field and the ambient electrostatic field have no effect on the path of the electron. The second method assumes that the electrons are trapped by the earth's magnetic field at the altitude of the X-ray-electron collision. Modifications were made to the ZAP procedure to provide for the use of source angle,source energy,and path length biasing. The PFLASH procedure was modified to allow for calculation of the standard deviation of the computed results. Biased sampling schemes for picking distances between collisions and the polar and azimuthal angle of scattering were incorporated in FLASH. An option was incorporated in FLASH and DFLASH for printing their results as a function of the retarded time. A study was performed to determine the effect of varying the size of the air fluorescence source volumes used in FLASH on the results generated by FLASH. A method of determining the size of the volume increments is outlined. (Author)