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in creator/contributor: "Moody, J. D."  
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Measurements of near forward scattered laser light in a large ICF plasma

Description: We describe an instrument which measures the angular spread and spectrum of near forward scattered laser light from a probe beam in a long scalelength laser-plasma. The instrument consists of a combination of time integrating and time resolving detectors which measure the scattered light amplitude over four orders of magnitude for a range of angles. These measurements allow us to study the beam spray resulting from various laser and plasma conditions and determine the density fluctuations assoc… more
Date: June 2, 1998
Creator: Moody, J. D.
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Partner: UNT Libraries Government Documents Department
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Characterization of the Series 1000 Camera System

Description: The National Ignition Facility requires a compact network addressable scientific grade CCD camera for use in diagnostics ranging from streak cameras to gated x-ray imaging cameras. Due to the limited space inside the diagnostic, an analog and digital input/output option in the camera controller permits control of both the camera and the diagnostic by a single Ethernet link. The system consists of a Spectral Instruments Series 1000 camera, a PC104+ controller, and power supply. The 4k by 4k CCD … more
Date: April 7, 2004
Creator: Kimbrough, J. R.; Moody, J. D.; Bell, P. M. & Landen, O. L.
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Partner: UNT Libraries Government Documents Department
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Imaging back scattered and near back scattered light in ignition scale plasmas

Description: Diagnostics have been developed and fielded at the Nova laser facility that image scattered light in the vicinity of the final laser focusing lens. The absolute calibration of optical components exposed to the target debris have been achieved by a combination of routine in situ calibration and maintenance. The scattering observed from plasmas relevant to ignition experiments indicates that light scattered just outside the lens can be larger than that collected by the lens, and is a significant … more
Date: May 7, 1996
Creator: Kirkwood, R. K.; Back, C. A.; Glenzer, S. H. & Moody, J. D.
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Partner: UNT Libraries Government Documents Department
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Angular Dependence of 3 Omega 0/2 Spectra from Laser-produced Plasmas

Description: Scattered light at three-halves of the incident laser frequency from solid targets is observed at five different angles. When the incident laser intensity is low enough, rescattering of two plasmon decay (TPD) instability electron plasma waves by ion acoustic waves is not significant. In this regime, Thomson scattering measurements of the electron temperature and the plasma flow velocity allow quantitative comparison of the angular dependence of the spectrum to theory.
Date: August 25, 1999
Creator: Young, P.E.; Moody, J.D. & Rhizomes, W.
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Partner: UNT Libraries Government Documents Department
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Solid Deuterium-Tritium Surface Roughness In A Beryllium Inertial Confinement Fusion Shell

Description: Solid deuterium-tritium (D-T) fuel layers for inertial confinement fusion experiments were formed inside of a 2 mm diameter beryllium shell and were characterized using phase-contrast enhanced x-ray imaging. The solid D-T surface roughness is found to be 0.4 {micro}m for modes 7-128 at 1.5 K below the melting temperature. The layer roughness is found to increase with decreasing temperature, in agreement with previous visible light characterization studies. However, phase-contrast enhanced x-ray… more
Date: April 19, 2006
Creator: Kozioziemski, B J; Sater, J D; Moody, J D; Montgomery, D S & Gautier, C
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Partner: UNT Libraries Government Documents Department
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Modeling the Effects of IR Heating on the Fuel Layer Symetry in a Cryogenic NIF Ignition Target

Description: We use thermal conduction models to investigate the effects of tailored IR heating on the fuel layer symmetry within a target capsule supported inside of a National Ignition Facility (NIF) hohlraum. We calculate the layer thickness profile that would result from the IR heat distribution alone and in combination with additional temperature shimming of the cylindrical hohlraum wall. We use the same model to study the effect of convection within the high density tamping gas in the hohlraum. A seve… more
Date: August 22, 2003
Creator: Sanchez, J. J.; Giedt, W. H.; Kozioziemski, B. J.; London, R. L. & Moody, J. D.
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Partner: UNT Libraries Government Documents Department
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Imaging Detectors for 20-100 ke V X-ray Backlighters in HEDES Petawatt Experiments

Description: We are developing a petawatt laser for use as a high energy backlighter source in the 20{approx} 100 keV range. High energy x-ray backlighters will be essential for radiographing High-Energy- Density Experimental Science (HEDES) targets for NIF projects especially to probe implosions and high areal density planar samples. For these experiments we are employing two types of detectors: a columnar grown CsI scintillator coupled to a 2K x 2K CCD camera and a CdTe crystal with a special ASIC readout… more
Date: April 16, 2004
Creator: Wickersham, J E; Park, H; Bell, P M; Koch, J A; Landen, O L & Moody, J D
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Partner: UNT Libraries Government Documents Department
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Thermal Infrared Exposure of Cryogenic Indirect Drive ICF Targets

Description: Cryogenic inertial confinement fusion targets at the National Ignition Facility and the Laser Megajoule will be protected from thermal infrared radiation by a cold shroud. As the shroud is removed just before the laser pulse, infrared radiation will heat and possibly degrade the symmetry of the solid hydrogen fuel layer. A lumped component mathematical model has been constructed to calculate how long an indirect drive target can be exposed to thermal radiation before the fuel layer degrades. Th… more
Date: July 8, 2005
Creator: London, R. A.; Moody, J. D.; Sanchez, J. J.; Sater, J. D.; Haid, B. J. & Bittner, D. N.
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Partner: UNT Libraries Government Documents Department
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Laser Machining For Fabrication Of Hohlraums And Capsules

Description: Laser machining technology has been used to demonstrate the ability to rapidly perform jobs on all aspects of ICF targets. Lasers are able to rapidly perform modifications and repairs to the gold metal parts on hohlraums, make cuts in the delicate polymer parts of the hohlraum, and drill holes in the capsules to enable them to be filled with fuel. Lasers investigated in this work include 193 nm ArF and 248 nm KrF excimers and 810 nm chirped-pulse amplification Ti:Sapphire lasers. The excimer la… more
Date: June 24, 2005
Creator: Shirk, M. D.; Kelly, B. T.; Haynes, S. M.; Stuart, B. C.; Sanchez, J. J.; Moody, J. D. et al.
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Partner: UNT Libraries Government Documents Department
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Ideal Laser Beam Propagation through high temperature ignition hohlraum plasmas

Description: We demonstrate that a blue (3{omega}, 351 nm) laser beam with an intensity of 2 x 10{sup 15} W-cm{sup -2} propagates within the original beam cone through a 2-mm long, T{sub e}=3.5 keV high density (n{sub e} = 5 x 10{sup 20} cm{sup -3}) plasma. The beam produced less than 1% total backscatter; the resulting transmission is greater than 90%. Scaling of the electron temperature in the plasma shows that the plasma becomes transparent for uniform electron temperatures above 3 keV. These results are… more
Date: September 20, 2006
Creator: Froula, D H; Divol, L; Meezan, N; Dixit, S; Moody, J D; Pollock, B B et al.
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Partner: UNT Libraries Government Documents Department
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Parametric instabilities in large nonuniform laser plasmas

Description: The study of parametric instabilities in laser plasmas is of vital importance for inertial confinement fusion (ICF). The long scale-length plasma encountered in the corona of an ICF target provides ideal conditions for the growth of instabilities such as stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS), and filamentation. These instabilities can have detrimental effects in ICF and their characterization and understanding is of importance. Scattering instabilities are dri… more
Date: September 1, 1992
Creator: Baldis, H. A.; Montgomery, D. S.; Moody, J. D.; Estabrook, K. G.; Berger, R. L.; Kruer, W. L. et al.
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Partner: UNT Libraries Government Documents Department
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Comparison of Raman Scattering Measurements and Modeling in NIF Ignition Experiments

Description: Recent NIF indirect-drive experiments have shown significant Raman scattering from the inner beams. NIF data has motivated improvements to rad-hydro modeling, leading to the 'high flux model' [M. D. Rosen et al., HEDP 7, 180 (2011)]. Cross-beam energy transfer [P. A. Michel et al., Phys. Plasmas 17, 056305 (2010] in the laser entrance hole is an important tool for achieving round implosions, and is uniformly distributed across the laser spot in rad-hydro simulations (but not necessarily in expe… more
Date: November 4, 2011
Creator: Strozzi, D. J.; Hinkel, D. E.; Williams, E. A.; Town, R. J.; Michel, P. A.; Divol, L. et al.
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Partner: UNT Libraries Government Documents Department
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Laser Beam Propagation through Inertial Confinement Fusion Hohlraum Plasmas

Description: A study of the relevant laser-plasma interaction processes has been performed in long-scale length plasmas that emulate the plasma conditions in indirect drive inertial confinement fusion targets. Experiments in this high-temperature (T{sub e} = 3.5 keV), dense (n{sub e} = 0.5 - 1 x 10{sup -3}) hohlraum plasma have demonstrated that blue 351-nm laser beams produce less than 1% total backscatter resulting in transmission greater than 90% for ignition relevant laser intensities (I < 2 x 10{sup… more
Date: October 26, 2006
Creator: Froula, D. H.; Divol, L.; Meezan, N. B.; DIxit, S.; Neumayer, P.; Moody, J. D. et al.
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Partner: UNT Libraries Government Documents Department
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Experimental Studies of Convection Effects in a Cryogenic NIF Ignition Target

Description: We describe experiments which investigate convection effects on hydrogen ice layers in a transparent CH capsule suspended with a fill-tube. These experiments validate simulations which show that unmitigated convection from the hohlraum fill gas can produce significant distortions to the cryogenic hydrogen ice layer. Experimental results show good agreement with thermal simulations which include conduction and convection.
Date: August 22, 2003
Creator: Moody, J. D.; Sanchez, J. J.; Bittner, D. N.; Giedt, W. H.; London, R. L.; Sater, J. D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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