Publications by authors named "M Dozieres"
Article Synopsis
- * Extended X-ray Absorption Fine Structure (EXAFS) is an effective technique for assessing material temperature and density for certain elements under dynamic compression.
- * The National Ignition Facility has created different configurations for EXAFS measurements using advanced x-ray sources and curved-crystal spectrometers to improve material analysis in both standard and extreme conditions.
Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment.
Phys Rev Lett
February 2024
Article Synopsis
- * This experiment produced 2.05 MJ of laser energy, resulting in 3.1 MJ of total fusion yield, which exceeds the Lawson criterion for ignition, demonstrating a key milestone in fusion research.
- * The report details the advancements in target design, laser technology, and experimental methods that contributed to this historic achievement, validating over five decades of research in laboratory fusion.
Article Synopsis
- Strong shocks are critical in high-energy-density environments, like inertial confinement fusion, but spatial measurements of these shocks are limited.
- This study utilized an imaging spectrometer to examine soft x-ray emissions from shock fronts in helium-neon mixtures and pure neon, finding that the shock width in the helium mixture is approximately double that in pure neon.
- The research indicates distinct precursor layers in both gases, with higher electron temperatures in the helium mixture, and simulations reveal that thermal conduction and ion kinetics significantly influence precursor formation and shock characteristics.
The Imaging Spectroscopy Snout (ISS) used at the National Ignition Facility is able to simultaneously collect neutron pinhole images, 1D spatially resolved x-ray spectra, and time resolved x-ray pinhole images. To measure the x-ray spectra, the ISS can be equipped with up to four different transmission crystals, each offering different energy ranges from ∼7.5 to ∼12 keV and different resolutions.
View Article and Find Full Text PDFA new class of crystal shapes has been developed for x-ray spectroscopy of point-like or small (a few mm) emission sources. These optics allow for dramatic improvement in both achievable energy resolution and total throughput of the spectrometer as compared with traditional designs. This class of crystal shapes, collectively referred to as the Variable-Radii Spiral (VR-Spiral), utilize crystal shapes in which both the major and minor radii are variable.
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