Neutral Beam Interactions with Materials.
Abstract
The basic approach involves coupling a one-dimensional hydrodynamic code to an ionization dynamics and an energy deposition model. Radiation emitted by the plasma is an important diagnostic tool, we have the model the ionization dynamics is very carefully accomplished by developing an ionization dynamics model which considers a large number of excited states and atomic processes. The atomic processes which are considered in our model are: 1) collisional ionization; 2) three body recombination; 3) collisional excitation; 4) collisional de-excitation; 5) spontaneous emission; 6) radiative recombination; 7) dielectric recombination. A model to calculate the stopping power for energetic, structured (those carrying electrons into the target) low Z ions has been developed. Low Z ions are both energetic and structured at typical specific energies of a few hundred keV/amu (e.g. 1 MeV helium). The atomic structure is taken into account by describing the electron cloud of the projectile with elastic form factors in the first Born approximation. However, at these energies the first Born approximation begins to break down. Hence, two corrections are included: the Bloch correction to account for the scattering of wave packets (instead of plane waves) for close collisions, and the Barkas effect which corrects for deviations from pure Rutherford scattering due to the displacement of an oscillating electron. Structure is introduced more approximately in these two terms. An attempt has been made to allow sufficient generality to describe ionized targets as well as neutral solids.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 22, 1985
- Accession Number
- ADA162330
Entities
People
- J. J. Duderstadt
- R. M. Gilgenbach
- R. S. Ong
Organizations
- University of Michigan