Publications

Journal of Quantitative Spectroscopy and Radiative Transfer

Nash, Thomas J.; Sanford, T.W.L.; Mock, R.C.; Leeper, Ramon J.; Chandler, Gordon A.; Bailey, James E.; Mckenney, John M.; Mehlhorn, Thomas A.; Seaman, J.F.; McGurn, John S.; Schroen, D.; Russell, C.; Lake, P.E.; Jobe, D.O.; Gilliland, Terrance L.; Nielsen, D.S.; Lucas, J.; Moore, T.; Torres, J.A.; Macfarlane, Joseph J.; Apruzese, J.P.; Chrien, R.; Idzorek, G.; Peterson, D.L.; Watt, R.

We present results from crystal spectroscopic analysis of silicon aero-gel foams heated by dynamic hohlraums on Z. The dynamic hohlraum on Z creates a radiation source with a 230-eV average temperature over a 2.4-mm diameter. In these experiments silicon aero-gel foams with 10 - mg/cm3 densities and 1.7-mm lengths were placed on both ends of the dynamic hohlraum. Several crystal spectrometers were placed both above and below the z-pinch to diagnose the temperature of the silicon aero-gel foam using the K-shell lines of silicon. The crystal spectrometers were (1) temporally integrated and spatially resolved, (2) temporally resolved and spatially integrated, and (3) both temporally and spatially resolved. The results indicate that the dynamic hohlraum heats the silicon aero-gel to approximately 150-eV at peak power. As the dynamic hohlraum source cools after peak power the silicon aero-gel continues to heat and jets axially at an average velocity of approximately 50-cm/μs. The spectroscopy has also shown that the reason for the up/down asymmetry in radiated power on Z is that tungsten enters the line-of-sight on the bottom of the machine much more than on the top. © 2004 Elsevier Ltd. All rights reserved.

Sanford, Thomas W.; Sanford, Thomas W.; Mock, Raymond M.; Gilliland, Terrance L.; Seamen, Johann F.; Leeper, Ramon J.

Abstract not provided.

Proposed for publication in Physical Review E.

Stygar, William A.; Matzen, M.K.; Mazarakis, Michael G.; McDaniel, Dillon H.; McGurn, John S.; Mckenney, John M.; Mix, L.P.; Muron, David J.; Ramirez, Juan J.; Ruggles, Larry R.; Stygar, William A.; Seamen, Johann F.; Simpson, Walter W.; Speas, Christopher S.; Spielman, Rick B.; Struve, Kenneth W.; Vesey, Roger A.; Wagoner, Tim C.; Gilliland, Terrance L.; Bennett, Guy R.; Ives, Harry C.; Jobe, Daniel O.; Lazier, Steven E.; Mills, Jerry A.; Mulville, Thomas D.; Pyle, John H.; Romero, Tobias M.; Seamen, Johann F.; Serrano, Jason D.; Smelser, Ruth S.; Fehl, David L.; Cuneo, M.E.; Bailey, James E.; Bliss, David E.; Chandler, Gordon A.; Leeper, Ramon J.

Abstract not provided.

Physics of Plasmas

Cuneo, M.E.; Vesey, Roger A.; Porter, John L.; Chandler, Gordon A.; Fehl, David L.; Gilliland, Terrance L.; Hanson, David L.; McGurn, John S.; Reynolds, Paul G.; Ruggles, Larry R.; Seamen, Hans; Spielman, Rick B.; Struve, Kenneth W.; Stygar, William A.; Simpson, Walter W.; Torres, Jose A.; Wenger, D.F.; Hammer, James H.; Rambo, Peter W.; Peterson, Darrell L.; Idzorek, George C.

Initial experiments to study the Z-pinch-driven hohlraum high-yield inertial confinement fusion (ICF) concept of Hammer, Tabak, and Porter [Hammer et al., Phys. Plasmas 6, 2129 (1999)] are described. The relationship between measured pinch power, hohlraum temperature, and secondary hohlraum coupling ("hohlraum energetics") is well understood from zero-dimensional semianalytic, and two-dimensional view factor and radiation magnetohydrodynamics models. These experiments have shown the highest x-ray powers coupled to any Z-pinch-driven secondary hohlraum (26±5 TW), indicating the concept could scale to fusion yields of >200 MJ. A novel, single-sided power feed, double-pinch driven secondary that meets the pinch simultaneity requirements for polar radiation symmetry has also been developed. This source will permit investigation of the pinch power balance and hohlraum geometry requirements for ICF relevant secondary radiation symmetry, leading to a capsule implosion capability on the Z accelerator [Spielman et al., Phys. Plasmas 5, 2105 (1998)]. © 2001 American Institute of Physics.