TuFF4. Half-integer harmonic emission from laser plasmas as a coronal temperature diagnostic

Journal Article · Fri Jun 01 04:00:00 EDT 1984 · J. Opt. Soc. Am. B: Opt. Phys.; (United States)

OSTI ID:6230083

Seka, W; Short, R W; Goldman, L M; Letzring, S; Richardson, M C; Soures, J M; Tanaka, K; Craxton, R S; Delettrez, J; Boni, R; Quick, D

Light emission at omega/sub 0//2 and 3omega/sub 0//2 from laser plasmas has long been observed and associated principally with the 2omega/sub rho/ decay instability at n/sub c//4. Various theories have been developed to explain the spectra of this emission, which exhibits generally broad double-line features with a temperature-dependent splitting. Recent omega/sub 0//2 spectra have, however, clearly shown additional features. Spherical target experiments with overlapping beams for optimum illumination uniformity are expected to exhibit more one-dimensional plasma blow-off behavior. Thus, predictions from one-dimensional theories adapted to spherical geometry should be applicable. The authors have tested this hypothesis on OMEGA with six overlapping UV (351-nm) beams on spherical targets. From these experiments the authors conclude that a much more one-dimensional plasma corona is indeed observed. However, the 3omega/sub 0//2 spectra observed under these conditions hardly lend themselves to quantitative coronal temperature diagnosis owing to the complex averaging of the spectra over the various angles of incidence on the spherical target surface as well as the various angles of emission with respect to the incident light. In contrast, the omega/sub 0//2 spectra show a somewhat more complex structure, one component of which is well suited to coronal temperature diagnosis.

• Research Organization: Univ. of Rochester, NY
• OSTI ID: 6230083
• Journal Information: J. Opt. Soc. Am. B: Opt. Phys.; (United States), Journal Name: J. Opt. Soc. Am. B: Opt. Phys.; (United States) Vol. 1:3; ISSN JOBPD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
CONFIGURATION
DATA
ELECTROMAGNETIC RADIATION
ELECTRON TEMPERATURE
EMISSION SPECTRA
EMISSION SPECTROSCOPY
EXPERIMENTAL DATA
FOCUSING
HARMONICS
INFORMATION
ION TEMPERATURE
LASER-PRODUCED PLASMA
NUMERICAL DATA
OSCILLATIONS
PLASMA
PLASMA DIAGNOSTICS
RADIATIONS
SPECTRA
SPECTROSCOPY
SPHERICAL CONFIGURATION
ULTRAVIOLET RADIATION