High resolution >40 keV x-ray radiography using an edge-on micro-flag backlighter at NIF-ARC.
Rev Sci Instrum
; 92(3): 033535, 2021 Mar 01.
Article
in En
| MEDLINE
| ID: mdl-33820053
ABSTRACT
Radiography of low-contrast features in high-density materials evolving on a nanosecond timescale requires a bright photon source in the tens of keV range with high temporal and spatial resolution. One application for sources in this category is the study of dynamic material strength in samples compressed to Mbar pressures at the National Ignition Facility, high-resolution measurements of plastic deformation under conditions relevant to meteor impacts, geophysics, armor development, and inertial confinement fusion. We present radiographic data and the modulation transfer function (MTF) analysis of a multi-component test object probed at â¼100 keV effective backlighter energy using a 5 µm-thin dysprosium foil driven by the NIF Advanced Radiographic Capability (ARC) short-pulse laser (â¼2 kJ, 10 ps). The thin edge of the foil acts as a bright line-projection source of hard x rays, which images the test object at 13.2× magnification into a filtered and shielded image plate detector stack. The system demonstrates a superior contrast of shallow (5 µm amplitude) sinusoidal ripples on gold samples up to 90 µm thick as well as enhanced spatial and temporal resolution using only a small fraction of the laser energy compared to an existing long-pulse-driven backlighter used routinely at the NIF for dynamic strength experiments.
Full text:
1
Database:
MEDLINE
Language:
En
Journal:
Rev Sci Instrum
Year:
2021
Type:
Article
Affiliation country:
United kingdom