U.S. Department of EnergyOffice of Scientific and Technical Information
Laser Beam Propagation through Long Ignition Scale Plasmas on NIF
Abstract
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 (3{omega}) with a total intensity of 2 x 10{sup 15}W cm{sup -2}. The targets were filled with 1 atm of CO{sub 2} producing of up to 7 mm long homogeneously heated plasmas with densities of n{sub e} = 5 x 10{sup 20} cm{sup -3} and temperatures of T{sub e} = 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 {approx}1 ns of the experiment when applying full laser beam smoothing consisting of phase plates, smoothing by spectral dispersion and polarizationmore »
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 877840
- Report Number(s):
- UCRL-CONF-213150
Journal ID: ISSN 0730--9244; TRN: US0601710
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Conference
- Resource Relation:
- Conference: Presented at: IEEE International Conference on Plasma Science, Monterey, CA, United States, Jun 20 - Jun 24, 2005
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 42 ENGINEERING; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BACKSCATTERING; BENCHMARKS; IGNITION; LASERS; PLASMA; PLATES; POLARIZATION; SIMULATION; TARGETS; US NATIONAL IGNITION FACILITY; VELOCITY
Citation Formats
Glenzer, S H. Laser Beam Propagation through Long Ignition Scale Plasmas on NIF. United States: N. p., 2005.
Web. doi:10.1109/PLASMA.2005.359103.
Glenzer, S H. Laser Beam Propagation through Long Ignition Scale Plasmas on NIF. United States. https://doi.org/10.1109/PLASMA.2005.359103
Glenzer, S H. 2005.
"Laser Beam Propagation through Long Ignition Scale Plasmas on NIF". United States. https://doi.org/10.1109/PLASMA.2005.359103. https://www.osti.gov/servlets/purl/877840.
@article{osti_877840,
title = {Laser Beam Propagation through Long Ignition Scale Plasmas on NIF},
author = {Glenzer, S H},
abstractNote = {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 (3{omega}) with a total intensity of 2 x 10{sup 15}W cm{sup -2}. The targets were filled with 1 atm of CO{sub 2} producing of up to 7 mm long homogeneously heated plasmas with densities of n{sub e} = 5 x 10{sup 20} cm{sup -3} and temperatures of T{sub e} = 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 {approx}1 ns of the experiment when applying full laser beam smoothing consisting of phase plates, smoothing by spectral dispersion and polarization smoothing. Measurements that only apply phase plates show laser beam filamentation and reduced propagation speed. 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.},
doi = {10.1109/PLASMA.2005.359103},
url = {https://www.osti.gov/biblio/877840},
journal = {},
issn = {0730--9244},
number = ,
volume = ,
place = {United States},
year = {Sun Jun 12 00:00:00 EDT 2005},
month = {Sun Jun 12 00:00:00 EDT 2005}
}