Development of an X-Ray Transport Model Based on Peierls' Integral Equation.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
An X-ray transport model is developed which gives the streaming radiation flux, thermal radiation flux, and material energy of air, as a function of position and time, following the release of a large amount of x-ray energy in the atmosphere. The model is intended as a compromise between the simple diffusion theory models and the accurate transport theory models. It applies to the radiative growth which takes place at early times before hydrodynamic motion begins. The model assumes that air is heated by photoelectric absorptions to a burnout temperature, the kinetic temperature at which the air molecules are completely ionized. The opacity of air is assumed very large at temperatures below the burnout temperature and very small at temperatures above the burnout temperature. Peierls integral equation is used to calculate the flux of thermal radiation which builds up in the burned-out air. The integral equation considers both the nonlocal and retarded time-dependent characteristics of the radiation field. An efficient numerical solution to the model is greatly complicated due to the inverse cubic temperature dependence of the opacity and the retarded time dependence of the thermal radiation field. A numerical algorithm is presented for solving the model. Author
- Nuclear Physics and Elementary Particle Physics