14 research outputs found
Reduced reshock growth in a convergent/divergent system: Effect of reshock strength
The Richtmyer-Meshkov instability creates or seeds
hydrodynamic instabilities that will mix cold shell material into the hot DT
fuel in an ignition capsule and may prevent ignition. Characteristic of this
process is multiple shocks crossing converging interfaces. To mimic this
situation, strong converging shocks were created, passed over an unstable
interface, reflected by an inner cylinder, and then reshocked the interface.
Analysis of the mix width at the unstable surface shows no additional
growth, within experimental uncertainty, due to an initially perturbed
surface and no dependence on reshock strength
calibration of the Gamma Reaction History instrument using reference samples (āpucksā) for areal density measurements
The introduction of a sample of carbon, for example a disk or āpuckā, near an imploding DT-filled capsule creates a source of 12C gamma rays that can serve as a reference for calibrating the response of the Gamma Reaction History (GRH) detector [1]. Such calibration is important in the measurement of ablator areal density āØĻRā©abl in plastic-ablator DT-filled capsules at OMEGA [2], by allowing āØĻRā©abl to be inferred as a function of ratios of signals rather than from absolute measurements of signal magnitudes. Systematic uncertainties in signal measurements and detector responses therefore cancel, permitting more accurate measurements of āØĻRā©abl
In situ calibration of the Gamma Reaction History instrument using reference samples (āpucksā) for areal density measurements
The introduction of a sample of carbon, for example a disk or āpuckā, near an imploding DT-filled capsule creates a source of 12C gamma rays that can serve as a reference for calibrating the response of the Gamma Reaction History (GRH) detector [1]. Such calibration is important in the measurement of ablator areal density āØĻRā©abl in plastic-ablator DT-filled capsules at OMEGA [2], by allowing āØĻRā©abl to be inferred as a function of ratios of signals rather than from absolute measurements of signal magnitudes. Systematic uncertainties in signal measurements and detector responses therefore cancel, permitting more accurate measurements of āØĻRā©abl