Published November 11, 2003 | Version v1
Report

Progress in Long Scale Length Laser-Plasma Interactions

Description

The first experiments on the National Ignition Facility (NIF) have employed the first four beams to measure propagation and laser backscattering losses in large ignition-size plasmas. Gas-filled targets between 2 mm and 7 mm length have been heated from one side by overlapping the focal spots of the four beams from one quad operated at 351 nm (3ω) with a total intensity of 2 x 1015 W cm-2. The targets were filled with 1 atm of CO2 producing of up to 7 mm long homogeneously heated plasmas with densities of ne = 6 x 1020 cm-3 and temperatures of Te = 2 keV. The high energy in a NIF quad of beams of 16kJ, illuminating the target from one direction, creates unique conditions for the study of laser plasma interactions at scale lengths not previously accessible. The propagation through the large-scale plasma was measured with a gated x-ray imager that was filtered for 3.5 keV x rays. These data indicate that the beams interact with the full length of this ignition-scale plasma during the last ∼1 ns of the experiment. During that time, the full aperture measurements of the stimulated Brillouin scattering and stimulated Raman scattering show scattering into the four focusing lenses of 6% for the smallest length (∼2 mm). increasing to 12% for ∼7 mm. These results demonstrate the NIF experimental capabilities and further provide a benchmark for three-dimensional modeling of the laser-plasma interactions at ignition-size scale lengths

Availability note (English)

Available from PURL: https://www.osti.gov/servlets/purl/15006528-ed32Eg/native/

Additional details

Publishing Information

Imprint Pagination
10.6 Megabytes
Report number
UCRL-CONF--155301

Conference

Title
3. International Conference on Inertial Fusion Sciences and Applications (IFSA)
Dates
7-12 Sep 2003
Place
Monterey, CA (United States)

INIS

Country of Publication
United States
Country of Input or Organization
United States
INIS RN
35032900
Subject category
S70: PLASMA PHYSICS AND FUSION TECHNOLOGY;
Resource subtype / Literary indicator
Conference, Non-conventional Literature
Descriptors DEI
BACKSCATTERING; BEAM-PLASMA SYSTEMS; BENCHMARKS; BRILLOUIN EFFECT; ELECTRON DENSITY; ELECTRON TEMPERATURE; LASER RADIATION; LASER TARGETS; LASER-PRODUCED PLASMA; PLASMA DENSITY; PLASMA DIAGNOSTICS; SIMULATION; US NATIONAL IGNITION FACILITY
Descriptors DEC
COHERENT SCATTERING; ELECTROMAGNETIC RADIATION; PLASMA; RADIATIONS; SCATTERING; TARGETS

Optional Information

Contract/Grant/Project number
W-7405-ENG-48
Notes
PDF-FILE: 9
Funding organization
US Department of Energy (United States)