Near to backscattered light imaging diagnostic on the National Ignition Facility
The National Ignition Facility (NIF) is being built at Lawrence Livermore National Laboratory for the U.S. Department of Energy Stockpile Stewardship Program. It will perform experiments for inertial confinement fusion ignition, high energy density science, and basic science. A target diagnostic is being developed for the NIF that will image nearly all the light scattered near the laser axis, (i.e., just outside the laser focusing lens). The diagnostic is called the near backscatter imager (NBI) and is presently required to measure stimulated Brillouin (SBS) and stimulated Raman (SRS) scattering so that the backscatter fraction will be determined with a goal of 30% uncertainty, and SBS and SRS temporal response with {approx}200 ps resolution. The NBI will also provide an option to measure temporally resolved spectrum with 50 ps and {approx}1 nm resolution. The diagnostic will obtain SBS and SRS scatter plate images with a retro-viewing optical digital camera placed inside the target chamber. Time integrated optical diodes and fast optical diodes will be placed at several locations on the scatter plate to obtain the power and total energy data, as well as a calibration for the scatter plate image at several points. Fibers will be placed near the diodes to provide the option to make spectral measurement. A calibration system using a low power laser, in situ, to illuminate a series of points on the plate while recording the plate image with an external camera system is also being considered.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40204877
- Journal Information:
- Review of Scientific Instruments, Vol. 72, Issue 1; Other Information: Othernumber: RSINAK000072000001000976000001; 609101CON; PBD: Jan 2001; ISSN 0034-6748
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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