Sub-keV design for the National Ignition Facility’s soft x-ray Opacity Spectrometer (OpSpec) and expansion plans for time-resolved measurements
Abstract
When compared with the National Ignition Facility’s (NIF) original soft x-ray opacity spectrometer, which used a convex cylindrical design, an elliptically shaped design has helped to increase the signal-to-noise ratio and eliminated nearly all reflections from alternate crystal planes. The success of the elliptical geometry in the opacity experiments has driven a new elliptical geometry crystal with a spectral range covering 520–1100 eV. When coupled with the primary elliptical geometry, which spans 1000–2100 eV, the new sub-keV elliptical geometry helps to cover the full iron L-shell and major oxygen transitions important to solar opacity experimentation. The new design has been built and tested by using a Henke x-ray source and shows the desired spectral coverage. Additional plans are underway to expand these opacity measurements into a mode of time-resolved detection, ∼1 ns gated, but considerations for the detector size and photometrics mean a crystal geometry redesign. The new low-energy geometry, including preliminary results from the NIF opacity experiments, is presented along with the expansion plans into a time-resolved platform.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 01, 2022
- Source ID
- 10.1063/5.0101704
Entities
People
- Christopher Fontes
- D. A. Max
- Eric Dutra
- J. A. Emig
- J. Ayers
- J. Buscho
- J. M. Heinmiller
- Ken Moy
- M S Wallace
- R. A. Knight
- R. Posadas
- Robert Heeter
- T. N. Archuleta
- Theodore S. Perry
- Todd Urbatsch
- Yekaterina Opachich
Organizations
- Lawrence Livermore National Laboratory
- Los Alamos National Laboratory
- Nevada National Security Site
- United States Department of Energy