Year: 2024
Type: article
Abstract: A rapid calibration system is under development for the Near Backscatter Imager (NBI) in use at the National Ignition Facility (NIF). NBI is an optical diagnostic that quantifies the stimulated Brillouin and Raman backscatter produced by NIF's targets. Specifically, NBI measures the light that does not fall directly back into the laser aperture, which is measured by the Full Aperture Backscatter System (FABS). When working in tandem with FABS, NBI allows for the full characterization of backscattered light. This informs Hohlraum laser coupling, optical damage, and laser-plasma interaction models. NBI uses a large Spectralon plate covered by a protective glass layer and is mounted inside the target chamber where it is exposed to high energy backscatter, neutrons, and build-up debris left over from the exploded targets. This gradually alters the reflectivity of the plate, meaning that NBI needs to be calibrated regularly. Described here is NIF's design for a system capable of rapid in situ calibration of NBI that is to be installed in FY25.
Source: Review of Scientific Instruments
DOI: 10.1063/5.0219559
Authors: H. J. Meyer, C. Bruulsema, E. R. Tubman, G. F. Swadling, J. D. Moody, N. Lemos, J. S. Ross
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G1356433355
OpenAlex ID: W4402364799