X-ray area backlighter development at the National Ignition Facility (invited)

M A Barrios; S P Regan; K B Fournier; R Epstein; R Smith; A Lazicki; R Rygg; D E Fratanduono; J Eggert; H-S Park; C Huntington; D K Bradley; O L Landen; G W Collins

doi:10.1063/1.4891713

X-ray area backlighter development at the National Ignition Facility (invited)

Rev Sci Instrum. 2014 Nov;85(11):11D502. doi: 10.1063/1.4891713.

Authors

M A Barrios¹, S P Regan², K B Fournier¹, R Epstein², R Smith¹, A Lazicki¹, R Rygg¹, D E Fratanduono¹, J Eggert¹, H-S Park¹, C Huntington¹, D K Bradley¹, O L Landen¹, G W Collins¹

Affiliations

¹ Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
² Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.

PMID: 25430176
DOI: 10.1063/1.4891713

Abstract

1D spectral imaging was used to characterize the K-shell emission of Z ≈ 30-35 and Z ≈ 40-42 laser-irradiated foils at the National Ignition Facility. Foils were driven with up to 60 kJ of 3ω light, reaching laser irradiances on target between 0.5 and 20 × 10(15) W/cm(2). Laser-to-X-ray conversion efficiency (CE) into the Heα line (plus satellite emission) of 1.0%-1.5% and 0.15%-0.2% was measured for Z ≈ 30-32 and Z ≈ 40-42, respectively. Measured CE into Heα (plus satellite emission) of Br (Z = 35) compound foils (either KBr or RbBr) ranged between 0.16% and 0.29%. Measured spectra are compared with 1D non-local thermodynamic equilibrium atomic kinetic and radiation transport simulations, providing a fast and accurate predictive capability.