Emission and Deposition of Charge Exchange Energy in a High Altitude Nuclear Explosion. Volume I. Diffusion of Debris Air Particles in an Exponential Atmosphere.
Abstract
The report studies the distribution in the ionosphere of debris particles that have escaped a fireball through charge exchange collisions. At altitudes where the mean free paths for ionization and charge exchange, (lambda sub i) + (lambda sub cx), respectively, are much smaller than the scale height h of the atmosphere, the particles simply diffuse around their guiding streamlines. To account for this spreading, a diffusion equation with an altitude-dependent diffusion coefficient is derived and solved. It is shown how this result may be extended to regimes where (lambda sub j) /h < or = l (j=i, cx) no longer pertains, i.e., to higher altitudes where a diffusion approximation is invalid. A simple extension of the theory is possible only when r, the ratio of charge exchange to ionization cross section, is less than unity. When r > or = 1, particles will spread significantly on their first charge exchange collision in a region where the diffusion theory is not applicable, and accurate account has to be taken of this initial non-diffusive spreading in order to obtain results in agreement with fact. A Monte-Carlo computer simulation was developed to corroborate the theory. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1973
- Accession Number
- AD0764955