9 research outputs found
Solid deuterium–tritium surface roughness in a beryllium inertial confinement fusion shell
Recommended from our members
Crystal growth and roughening of solid D{sub 2}
Near the triple point, growth shapes of vapor deposited hexagonal close packed D{sub 2} crystals reveal two crystal orientations contain facets which persist up to the melt. This observation is in contrast with previous experiments on rare gas solids and H{sub 2} where the highest T{sub r} measured is 0.8 T{sub tp}
Characterization of D-T cryogenic layer formation in a Beryllium capsule using X-ray phase contrast imaging
Copper-doped beryllium capsules filled with cryogenic deuterium and
tritium (D-T) fuel layers offer many technical and manufacturing
advantages for Inertial Confinement Fusion. However, characterizing
the frozen fuel layer in such targets is challenging since
traditional x-ray radiographic techniques, which rely on absorption
for image contrast, cannot provide sufficient contrast to image the
low-Z D-T fuel layer in these targets. In this research, we employ
x-ray phase contrast imaging (XPCI), which relies on gradients in
the object's phase, to produce image contrast. We find that XPCI has
sufficient sensitivity to characterize the D-T cryogenic layers in
an ignition-scale Be(Cu) capsule. A Be(Cu) capsule is filled with
liquid D-T via a small fill-tube, and is kept at a uniform
temperature below the D-T triple point in a cryostat designed to
produce spherical isotherms. A very uniform spherical D-T ice layer
( 1.5 m RMS roughness) is formed within the capsule after a
few hours due to heating by beta-decay of the tritium. Studies
performed for D-T layer uniformity show an increase in surface
roughness as the temperature is lowered. We discuss the source and
detector characteristics necessary to obtain high quality XPCI
images of the D-T layer, wave-propagation modeling of the image
formation process, and image analysis
Quantitative Radiography: Submicron Dimension Calibration for ICF Ablator Shell Characterization
Solid Hydrogen Experiments For Atomic Propellants: Particle Formation Energy And Imaging Analyses
Status of cryogenic layering for NIF ignition targets
Recent advances in cryogenic layering include the
development of a self-contained and self-filling hohlraum, application of
phase contrast x-ray measurements for ice layer characterization, and an ice
layer achieved with beta-layering which meets the NIF specification for
surface roughness at 1.5 K below the triple point. In addition, recent
results on target integration in a hohlraum show effective layer control
using heaters on the hohlraum