The coupling of stimulated Raman and Brillouin scattering in a plasma (open access)

The coupling of stimulated Raman and Brillouin scattering in a plasma

The observation of an anti-Stokes satellite in the spectrum of light backscattered from a CO{sub 2} laser plasma is reported. Its origin is found to be Thomson scattering of the incident light from a counterpropagating mode-coupled plasma wave. The parent electron and ion waves in the mode-coupling process were driven by stimulated Raman and Brillouin backscattering. The parent and daughter plasma waves were detected by ruby laser Thomson scattering. A computer simulation modeling the experiment shows further cascading of the Stokes backscattered light to lower frequencies, apparently due to its rescattering by another, higher phase velocity, counterpropagating coupled mode. Comparisons with theoretical predictions are presented. 16 refs., 4 figs.
Date: September 19, 1988
Creator: Umstadter, D.; Mori, W.B. & Joshi, C. (Lawrence Livermore National Lab., CA (USA))
Object Type: Report
System: The UNT Digital Library
Neutronics analysis of the Laboratory Microfusion Facility (open access)

Neutronics analysis of the Laboratory Microfusion Facility

The radiological safety hazards of the experimental area (EA) for the proposed Inertial Confinement Fusion (ICF) Laboratory Microfusion Facility (LMF) have been examined. The EA includes those structures required to establish the proper pre-shot environment, point the beams, contain the pellet yield, and measure many different facets of the experiments. The radiation dose rates from neutron activation of representative target chamber materials, the laser beam tubes and the argon gas they contain, the air surrounding the chamber, and the concrete walls of the experimental area are given. Combining these results with the allowable dose rates for workers, we show how radiological considerations affect access to the inside of the target chamber and to the diagnostic platform area located outside the chamber. Waste disposal and tritium containment issues are summarized. Other neutronics issues, such as radiation damage to the final optics and neutron heating of materials placed close to the target, are also addressed. 16 refs., 2 figs., 1 tab.
Date: September 19, 1988
Creator: Tobin, M. T.; Singh, M. S. & Meier, W. R.
Object Type: Article
System: The UNT Digital Library