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A study of CR-39 track response to charged particles from NOVA implosions

Description: We have exposed CR-39 track recording material to a number of NOVA implosions. Radiation from the implosion passed through an array of ranging filters, which aided identification of the incident particles and their energies. The etching procedure was calibrated by including a piece of track exposed to DD protons from a small accelerator. For the same shots, we quantitatively compare the DD neutron yield with the DD proton yield determined from the track. In DT implosions, tracks produced by neu… more
Date: June 14, 1996
Creator: Phillips, T. W.; Cable, M. D.; Hicks, D. G.; Li, C. K.; Petrasso, R. D. & Seguin, F. H.
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Partner: UNT Libraries Government Documents Department
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Design of an electronic charged particle spectrometer to measure ({rho}R), yield, and implosion symmetry on the OMEGA Upgrade

Description: The preliminary design for a state-of-the-art diagnostic that will measure a broad energy spectrum of charged particles generated in the OMEGA Upgrade facility is investigated. Using a set of photodiodes ({approximately}10) and a 0.8 Tesla permanent magnet, the diagnostic will uniquely determine particle energies and identities from 0.2 MeV up to the maximum charged particle energies (10.6 MeV tritons, 12.5 MeV deuterons and 17.4 MeV protons). With its high density picture elements, each photod… more
Date: November 1, 1994
Creator: Hicks, D. G.; Li, C. K.; Petrasso, R. D.; Wenzel, K. W. & Knauer, J. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Shock Compressing Diamond to a Conducting Fluid

Description: Laser generated shock reflectance data show that diamond undergoes a continuous transition from optically absorbing to reflecting between Hugoniot pressures 600<P{sub H}<1000 GPa. The data are consistent with diamond having a thermal population of carriers at P{sub H}{approx}600 GPa, undergoing band overlap metallization at P{sub H}{approx}1000 GPa and melting at 800<P{sub H}<1000 GPa. The results agree well with an equation of state model that predicts that elemental carbon remains… more
Date: July 29, 2004
Creator: Bradley, D K; Eggert, J H; Hicks, D G; Celliers, P M; Moon, S J; Cauble, R C et al.
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Partner: UNT Libraries Government Documents Department
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Shock-Compressed Diamond: Melt, Insulator-Conductor and Polymeric-Atomic Transitions

Description: Temperatures measured on the shock-Hugoniot of diamond reveal melting between 650 ({+-} 60) GPa and 9000 ({+-} 800) K and 1090 ({+-} 50) GPa and 8400 ({+-} 800) K, with a heat of fusion of {approx} 25 {+-} 10 kJ/mole and a negative Clapeyron slope {partial_derivative}T/{partial_derivative}P|{sub melt} = -5 {+-} 3 K/GPa. Thus, the fluid is denser than the compressed solid, and optical reflectivity measurements show it to be metallic. Hugoniot-temperature measurements extending to over 4000 GPa (… more
Date: August 16, 2007
Creator: Eggert, J; Hicks, D G; Celliers, P M; Bradley, D K; McWilliams, R S; Jeanloz, R et al.
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Partner: UNT Libraries Government Documents Department
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Properties of Fluid Deuterium under Double-Shock Compression to Several Mbar

Description: The compressibility of fluid deuterium up to several Mbar has been probed using laser-driven shock waves reflected from a quartz anvil. Combining high-precision ({approx} 1 %) shock velocity measurements with the double-shock technique, where differences in equation of state (EOS) models are magnified, has allowed us to accurately discriminate between various theoretical predictions. Our data are consistent with EOS models that show approximately fourfold compression on the principal Hugoniot f… more
Date: February 3, 2004
Creator: Vianello, E; Celliers, P M; Hicks, D G; Boehly, T R; Collins, T B; Moon, S J et al.
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Partner: UNT Libraries Government Documents Department
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Design Calculations For NIF Convergent Ablator Experiments

Description: The NIF convergent ablation tuning effort is underway. In the early experiments, we have discovered that the design code simulations over-predict the capsule implosion velocity and shock flash rhor, but under-predict the hohlraum x-ray flux measurements. The apparent inconsistency between the x-ray flux and radiography data implies that there are important unexplained aspects of the hohlraum and/or capsule behavior.
Date: October 25, 2011
Creator: Olson, R E; Hicks, D G; Meezan, N B; Callahan, D A; Landen, O L; Jones, O S et al.
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Partner: UNT Libraries Government Documents Department
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Imaging VISAR diagnostic for the National Ignition Facility (NIF)

Description: The National Ignition Facility (NIF) requires diagnostics to analyze high-energy density physics experiments. A VISAR (Velocity Interferometry System for Any Reflector) diagnostic has been designed to measure shock velocities, shock breakout times, and shock emission of targets with sizes from 1 to 5 mm. An 8-inch-diameter fused silica triplet lens collects light at f/3 inside the 30-foot-diameter vacuum chamber. The optical relay sends the image out an equatorial port, through a 2-inch-thick v… more
Date: August 30, 2004
Creator: Malone, R M; Bower, J R; Bradley, D K; Capelle, G A; Celeste, J R; Celliers, P M et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Using Vulcan to Recreate Planetary Cores

Description: An accurate equation of state (EOS) for planetary constituents at extreme conditions is the key to any credible model of planets or low mass stars. However, experimental validation has been carried out on at high pressure (>few Mbar), and then only on the principal Hugoniot. For planetary and stellar interiors, compression occurs from gravitational force so that material states follow a line of isentropic compression (ignoring phase separation) to ultra-high densities. An example of the pred… more
Date: August 15, 2001
Creator: Collins, G. W.; Celliers, P. M.; Hicks, D. G.; Mackinnon, A. J.; Moon, S. J.; Cauble, R. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Hohlraum Designs for High Velocity Implosions on NIF

Description: In this paper, we compare experimental shock and capsule trajectories to design calculations using the radiation-hydrodynamics code HYDRA. The measured trajectories from surrogate ignition targets are consistent with reducing the x-ray flux on the capsule by about 85%. A new method of extracting the radiation temperature as seen by the capsule from x-ray intensity and image data shows that about half of the apparent 15% flux deficit in the data with respect to the simulations can be explained b… more
Date: October 19, 2011
Creator: Meezan, N. B.; Hicks, D. G.; Callahan, D. A.; Olson, R. E.; Schneider, M. S.; Thomas, C. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Experimental Studies of ICF Indirect-Drive Be and High Density C Candidate Ablators

Description: To validate our modeling of the macroscopic and microscopic hydrodynamic and equation of state response of these candidate ablators to NIC-relevant x-ray drive, a multi-lab experimental program has been verifying the behavior of these new ablators. First, the pressures for onset and termination of melt for both Be and HDC under single or double shock drive has been measured at the Z and Omega facilities. Second, the level and effect of hard x-ray preheat has been quantified in scaled experiment… more
Date: September 5, 2007
Creator: Landen, O. L.; Bradley, D. K.; Braun, D. G.; Smalyuk, V. A.; Hicks, D. G.; Celliers, P. M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Shock timing on the National Ignition Facility: First Experiments

Description: An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF) was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a reentrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set … more
Date: October 24, 2011
Creator: Celliers, P. M.; Robey, H. F.; Boehly, T. R.; Alger, E.; Azevedo, S.; Berzins, L. V. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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