12 research outputs found
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Gain scaling laws for HIF
The relationship between target gain (thermonuclear energy-released/ion energy incident) and such factors as the total ion energy, the ion beam radius, the ion range, the ion power, the beam geometry, and the released target debris are critical in assessing the feasibility of a particular heavy ion inertial confinement fusion reactor concept. Scaling relationships that allow target gain to be calculated from the target hydrodynamic coupling efficiency (eta), the target radius (R), and the ion energy incident on the target (E/sub i/) are presented. These relations include scaling laws for the required peak power and ion energy, the fuel fractional burnup, and the fraction of energy released in charged particles and x-rays as a function of r, eta, and E/sub i/. Relations have been developed to two single-shell target concepts, one requiring two-sided and the other symmetric ion illumination
Statistical Survey of Type III Radio Bursts at Long Wavelengths Observed by the Solar TErrestrial RElations Observatory (STEREO)/Waves Instruments: Radio Flux Density Variations with Frequency
We have performed a statistical study of Type III radio bursts observed
by Solar TErrestrial RElations Observatory (STEREO)/Waves between May 2007 and
February 2013. We have investigated the flux density between kHz and
MHz. Both high- and low-frequency cutoffs have been observed in of
events suggesting an important role of propagation. As already reported by
previous authors, we observed that the maximum flux density occurs at MHz on
both spacecraft. We have developed a simplified analytical model of the flux
density as a function of radial distance and compared it to the STEREO/Waves
data.Comment: published in Solar Physic
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X-ray and pressure conditions on the first wall of a particle beam inertial confinement reactor
Because of the presence of a chamber gas in a particle beam reactor cavity, nonneutron target debris created from thermonuclear burn will be modified or stopped before it reaches the first reactor wall. The resulting modified spectra and pulse lengths of the debris need to be calculated to determine first wall effects. Further, the cavity overpressure created by the momentum and energy exchange between the debris and gas must also be calculated to determine its effect. The purpose of this paper is to present results of the debris-background gas problem obtained with a one fluid, two temperature plasma hydrodynamic computer code model which includes multifrequency radiation transport. Spherical symmetry, ideal gas equation of state, and LTE for each radiation frequency group were assumed. The transport of debris ions was not included and all the debris energy was assumed to be in radiation. The calculated x-ray spectra and pulse lengths and the background overpressure are presented
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
Defect-induced mix experiment for NIF
The Defect Induced Mix Experiment (DIME-II) will measure the implosion and mix characteristics of CH capsules filled with 5 atmospheres of DT by incorporating mid-Z dopant layers of Ge and Ga. This polar direct drive (PDD) experiment also will demonstrate the filling of a CH capsule at target chamber center using a fill tube. Diagnostics for these experiments include areal x-ray backlighting to obtain early time images of the implosion trajectory and a multiple-monochromatic imager (MMI) to collect spectrally-resolved images of the capsule dopant line emission near bangtime. The inclusion of two (or more) thin dopant layers at separate depths within the capsule shell facilitates spatial correlation of mix between the layers and the hot gas core on a single shot. The dopant layers are typically 2 μm thick and contain dopant concentrations of 1.5%. Three dimensional Hydra simulations have been performed to assess the effects of PDD asymmetry on capsule performance
Preparing for polar-drive ignition on the National Ignition Facility
The implementation of polar drive (PD) at the National Ignition Facility (NIF) will enable the execution of direct-drive implosions while the facility is configured for x-ray drive. The Laboratory for Laser Energetics (LLE), in collaboration with LLNL, LANL and GA, is implementing PD on the NIF. LLE has designed and participates in the use of PD implosions for diagnostic commissioning on the NIF. LLE has an active experimental campaign to develop PD in both warm and cryogenic target experiments on OMEGA. LLE and its partners are developing a Polar Drive Project Execution Plan, which will provide a detailed outline of the requirements, resources, and timetable leading to PD-ignition experiments on the NIF
Preparing for polar-drive ignition on the National Ignition Facility
The implementation of polar drive (PD) at the National Ignition Facility (NIF) will enable the execution of direct-drive implosions while the facility is configured for x-ray drive. The Laboratory for Laser Energetics (LLE), in collaboration with LLNL, LANL and GA, is implementing PD on the NIF. LLE has designed and participates in the use of PD implosions for diagnostic commissioning on the NIF. LLE has an active experimental campaign to develop PD in both warm and cryogenic target experiments on OMEGA. LLE and its partners are developing a Polar Drive Project Execution Plan, which will provide a detailed outline of the requirements, resources, and timetable leading to PD-ignition experiments on the NIF