Development of a Big Area BackLighter for high energy density experiments

K A Flippo; J L Kline; F W Doss; E N Loomis; M Emerich; B Devolder; T J Murphy; K B Fournier; D H Kalantar; S P Regan; M A Barrios; E C Merritt; T S Perry; I L Tregillis; L Welser-Sherrill; J R Fincke

doi:10.1063/1.4893349

Development of a Big Area BackLighter for high energy density experiments

Rev Sci Instrum. 2014 Sep;85(9):093501. doi: 10.1063/1.4893349.

Authors

K A Flippo¹, J L Kline¹, F W Doss¹, E N Loomis¹, M Emerich², B Devolder¹, T J Murphy¹, K B Fournier³, D H Kalantar³, S P Regan⁴, M A Barrios³, E C Merritt¹, T S Perry¹, I L Tregillis¹, L Welser-Sherrill¹, J R Fincke¹

Affiliations

¹ Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87507, USA.
² General Atomics, P.O. Box 85608, San Diego, California 92121, USA.
³ Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA.
⁴ Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.

PMID: 25273720
DOI: 10.1063/1.4893349

Abstract

A very large area (7.5 mm(2)) laser-driven x-ray backlighter, termed the Big Area BackLighter (BABL) has been developed for the National Ignition Facility (NIF) to support high energy density experiments. The BABL provides an alternative to Pinhole-Apertured point-projection Backlighting (PABL) for a large field of view. This bypasses the challenges for PABL in the equatorial plane of the NIF target chamber where space is limited because of the unconverted laser light that threatens the diagnostic aperture, the backlighter foil, and the pinhole substrate. A transmission experiment using 132 kJ of NIF laser energy at a maximum intensity of 8.52 × 10(14) W/cm(2) illuminating the BABL demonstrated good conversion efficiency of >3.5% into K-shell emission producing ~4.6 kJ of high energy x rays, while yielding high contrast images with a highly uniform background that agree well with 2D simulated spectra and spatial profiles.