# Accession Number:

## ADA167019

# Title:

## Calculation of Single- and Double-Photon Free-Free Cross Sections for Electrons Scattered from HE, C, N, NE and AR.

# Descriptive Note:

## Final rept. Sep 80-Feb 83,

# Corporate Author:

## NEW YORK UNIV NY DEPT OF PHYSICS

# Personal Author(s):

# Report Date:

## 1986-02-01

# Pagination or Media Count:

## 52.0

# Abstract:

Calculations of cross sections for the free-free absorption of radiation by electrons scattered from atoms are reported. The results apply in the limit where theory is valid, and are obtained in the context of a realistic independent particle atomic model, which facilitates numerical solutions for both perturbed and unperturbed wave functions. Both one photon and two photon absorptions are analyzed, the latter in a mixed gauge representation. The method is applied to several different atomic targets--the ground states of He, for frequencies corresponding to the 3S1 and 1So states of He, for frequencies corresponding to the carbon dioxide, neodymium, and ruby lasers. The low-frequency results agree well with the soft-photon approximation, while, as one might expect, the numbers at shorter wavelengths diverge. For all cases, it was found that the free-free cross sections were negligibly small compared to radiationless cross sections, for intensities no greater than 1000000 Wcc. Keywords Electron scattering Free-free radiation Perturbation theory Frequency dependence.

# Descriptors:

- *ELECTRON SCATTERING
- *TWO PHOTON ABSORPTION
- RADIATION
- COMPUTATIONS
- CARBON
- NITROGEN
- ELECTRONS
- ELECTRONIC STATES
- RADIATION ABSORPTION
- PERTURBATION THEORY
- PHOTONS
- HELIUM
- ABSORPTION
- WAVE FUNCTIONS
- ELECTRON TRANSITIONS
- ARGON
- ABSORPTION CROSS SECTIONS
- NEON
- CARBON DIOXIDE LASERS
- NEODYMIUM LASERS
- RUBY LASERS

# Subject Categories:

- Nuclear Physics and Elementary Particle Physics