Resonance Absorption of Laser Light by Warm and Cold Plasmas.
Abstract
This is a study of the mechanisms and results of resonance absorption in warm and cold plasmas. Maxwell's equations and the plasma fluid equations (neglecting ion motion and assuming wavelike solutions in the x-direction) are linearized. The linearization is accomplished for a plasma with a positive number density gradient in the z-direction. Second-order equations are derived from the linearized set. These second-order equations are differenced and solved in the z-direction for the TM mode of propagation using a two-sweep algorithm with zero and radiation boundary conditions. The characteristics of the field quantities are investigated at various temperatures. Further N sub 1 (the plasma wave), the temperature of the hot electrons, and the nonlinear Ponderomotive force are calculated. Finally, resonance absorption by the plasma is calculated and peak absorptions of 50% are observed for both cold and low temperature warm plasmas. The validity of the assumptions is discussed referencing both power and temperature concerns. Possible nonlinear and time-dependent modifications to the theory are discussed. Landau damping is derived and its limitations considered. The two-sweep algorithm is found to give accurate results and its amenability to computer application makes it a desirable method. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1981
- Accession Number
- ADA100802
Entities
People
- John H. Ruble Jr
Organizations
- Air Force Institute of Technology