Time resolved soft x-ray studies of energy transport in layered and planar laser-driven targets

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6204942

Stradling, G L

New low-energy x-ray diagnostic techniques are used to explore energy-transport processes in laser heated plasmas. Streak cameras are used for the first time to provide 15-psec time-resolution measurements of sub keV x-ray emission. A very thin (50 ..mu..g/cm/sup 2/) carbon substrate provides a low-energy x-ray window to the transmission photocathode of this soft x-ray streak camera. Active differential vacuum pumping of the instrument is required. X-ray spectral resolution, in the region below 1 keV which includes the spectral peak, is obtained through this initial use of the high-energy cutoff properties of x-ray reflectors with x-ray streak cameras. In this application absorption-edge filters provide spectral channel definition. Enhanced spectral resolution in five sub keV spectral bands, 10-eV wide, are made possible through the use of state-of-the-art metal-multilayer x-ray interference mirrors. These large d-spacing Bragg reflectors, which are synthesized elsewhere, provide great flexibility in sub keV photon energy-band selection and detector geometry. High peak reflectivity (10%) and intermediate bandwidths (10 eV) were obtained in this first low-energy application of these structures. The first use of high-sensitivity, low secondary-electron energy-spread, Csl photocathodes in x-ray streak cameras is also described. Significant increases in sensitivity with only a small and intermittant decrease in dynamic range were observed. The coherent, complementary advances in sub keV, time-resolved x-ray diagnostic capability are applied to energy-transport investigations of 1.06-..mu..m laser plasmas.

• Research Organization: California Univ., Davis (USA)
• OSTI ID: 6204942
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
ALKALINE EARTH METALS
ALUMINIUM
BERYLLIUM
BRAGG REFLECTION
COMPARATIVE EVALUATIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION
ENERGY RANGE
ENERGY TRANSFER
EV RANGE
EV RANGE 100-1000
HEATING
IONIZING RADIATIONS
IRRADIATION
LASER-PRODUCED PLASMA
LASER-RADIATION HEATING
LAYERS
METALS
PHOTOGRAPHY
PLASMA
PLASMA HEATING
RADIATIONS
REFLECTION
RESOLUTION
SOFT X RADIATION
SOLIDS
SPECTRA
STREAK PHOTOGRAPHY
TIME RESOLUTION
TIMING PROPERTIES
X RADIATION
X-RAY SPECTRA