Publications

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Development of the MARZ platform (Magnetically Ablated Reconnection on Z) to study astrophysically relevant radiative magnetic reconnection in the laboratory

Myers, Clayton E.; Hare, Jack H.; Ampleford, David A.; Aragon, Carlos A.; Chittenden, Jeremy P.; Colombo, Anthony P.; Crilly, Aidan C.; Datta, Rishabh D.; Edens, Aaron E.; Fox, Will F.; Gomez, Matthew R.; Halliday, Jack H.; Hansen, Stephanie B.; Harding, Eric H.; Harmon, Roger L.; Jones, Michael J.; Jennings, Christopher A.; Ji, Hantao J.; Kuranz, Carolyn K.; Lebedev, Sergey L.; Looker, Quinn M.; Melean, Raul M.; Uzdensky, Dmitri U.; Webb, Timothy J.

Abstract not provided.

Upgrading Wolter Imagers for X-Ray Diagnostics in the Z Pulsed-Power Facility at Sandia National Laboratories

Vogel, J K.; Kozioziemski, B K.; Walton, C C.; Ayers, J A.; Bell, Perry M.; Bradley, David K.; Descalle, M-A D.; Hau-Riege, S H.; Fein, Jeffrey R.; Ampleford, David A.; Ball, Christopher R.; Gard, Paul D.; Jones, Michael J.; Maurer, A.; Wu, Ming W.; Champey, P C.; Davis, J D.; Griffith, C G.; Kolodziejczak, J K.; Ramsey, B R.; Sanchez, J S.; Speegle, C S.; Young, M Y.; Kilaru, K K.; Roberts, O R.; Ames, A A.; Bruni, R B.; Romaine, S R.; Sethares, L S.

Abstract not provided.

Z Line-VISAR: A Spatially Resolved Load Current Diagnostic at the Z Pulsed Power Facility

Bliss, David E.; Myers, Clayton E.; Jones, Michael J.; Baker, J.L.; Austin, Kevin N.; Bettnecourt, R &.; Bliss, E.; Celeste, J.C.; Celliers, P.C.; Clancy, T.C.; Cohen, S.; Crosley, M.C.; Datte, P.D.; Erskine, D.E.; Fratanduono, D.E.; Frieders, G.F.; Galbraith, J.G.; Hammer, J.H.; Hess, Mark H.; Jackson, J.; Jennings, Christopher A.; Johnson, Drew J.; Koen, D.K.; Lusk, J.L.; Martinez, A.M.; Massey, W.M.; McCarville, T.J.; McDonald, R.; McLean, H.M.; Raman, K.S.; Rodriguez, S.R.; Spencer, Decker C.; Springer, P.S.; de Dios, G.V.; Wong, J.W.

Abstract not provided.

Daily operation of Z: an 80 TW 36-module pulsed power driver

Savage, Mark E.; Cuneo, M.E.; Davis, Jean-Paul D.; Hutsel, Brian T.; Jones, Michael J.; Jones, Peter A.; Kamm, Ryan J.; Lopez, Michael R.; Matzen, M.K.; McDaniel, D.H.M.; McKee, George R.; Maenchen, J.E.M.; Owen, A.C.O.; Porter, John L.; Prestwich, K.R.P.; Schwarz, Jens S.; Sinars, Daniel S.; Stoltzfus, Brian S.; Struve, Kenneth W.; Stygar, William A.; Wakeland, P.; White, William M.

Abstract not provided.

2-D RMHD modeling assessment of current flow, plasma conditions, and doppler effects in recent Z argon experiments

IEEE Transactions on Plasma Science

Thornhill, J.W.; Giuliani, John L.; Jones, Brent M.; Apruzese, John P.; Dasgupta, Arati; Chong, Young K.; Harvey-Thompson, Adam J.; Ampleford, David A.; Hansen, Stephanie B.; Coverdale, Christine A.; Jennings, Christopher A.; Rochau, G.A.; Cuneo, M.E.; Lamppa, Derek C.; Johnson, Drew J.; Jones, Michael J.; Moore, Nathan W.; Waisman, Eduardo M.; Krishnan, Mahadevan; Coleman, Philip L.

By varying current-loss circuit parameters, the Mach2-tabular collisional radiative equilibrium 2-D radiation magnetohydrodynamic model was tuned to reproduce the radiative and electrical properties of three recent argon gas-puff experiments (same initial conditions) performed on the Z machine at Sandia National Laboratories. The model indicates that there were current losses occurring near or within the diode region of the Z machine during the stagnation phase of the implosion. The 'good' simulation reproduces the experimental K-shell powers, K-shell yields, total powers, percentage of emission radiated in α lines, size of the K-shell emission region, and the average electron temperature near the time-of-peak K-shell power. The calculated atomic populations, ion temperatures, and radial velocities are used as input to a detailed multifrequency ray-trace radiation transport model that includes the Doppler effect. This model is employed to construct time-, space-, and energy-resolved synthetic spectra. The role the Doppler effect likely plays in the experiments is demonstrated by comparing synthetic spectra generated with and without this effect.

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Investigating the Effects of Adding a Center jet to Argon gas puff implosions at the Z facility

Harvey-Thompson, Adam J.; Jennings, Christopher A.; Jones, Brent M.; Ampleford, David A.; Hansen, Stephanie B.; Lamppa, Derek C.; Cuneo, M.E.; Reneker, Joseph R.; Johnson, Drew J.; Jones, Michael J.; Moore, Nathan W.; Flanagan, Timothy M.; Mckenney, John M.; Rochau, G.A.; Waisman, Eduardo M.; Coverdale, Christine A.; Apruzese, J.P.A.; Thornhill, J.W.T.; Giuliani, J.L.G.

Abstract not provided.

The effect of adding a center jet to Argon gas puff implosions at the Z facility

Harvey-Thompson, Adam J.; Jennings, Christopher A.; Jones, Brent M.; Ampleford, David A.; Hansen, Stephanie B.; Lamppa, Derek C.; Cuneo, M.E.; Reneker, Joseph R.; Johnson, Drew J.; Jones, Michael J.; Moore, N.W.M.; Flanagan, Timothy M.; Mckenney, John M.; Rochau, G.A.; Waisman, E.M.W.; Coverdale, Christine A.; Thornhill, J.W.T.; Giuliani, J.L.G.; Chong, Y.K.C.; Velikovich, A.L.V.; Dasgupta, A.D.; Apruzese, J.P.A.

Abstract not provided.

Modified 3D-helix-like instability structure for imploding Z-pinch liners that are premagnetized with a uniform axial field

Awe, Thomas J.; Jennings, Christopher A.; McBride, Ryan D.; Cuneo, M.E.; Lamppa, Derek C.; Martin, Matthew; Rovang, Dean C.; Sinars, Daniel S.; Slutz, Stephen A.; Owen, Albert C.; Gomez, Matthew R.; Hansen, Stephanie B.; Harding, Eric H.; Herrmann, Mark H.; Jones, Michael J.; Knapp, Patrick K.; Mckenney, John M.; Peterson, Kyle J.; Robertson, Grafton K.; Rochau, G.A.; Savage, Mark E.; Schmit, Paul S.; Sefkow, Adam B.; Stygar, William A.; Vesey, Roger A.; Yu, Edmund Y.; Tomlinson, Kurt T.; Schroen, Diana G.

Abstract not provided.

Modified helix-like instability structure on imploding z-pinch liners that are pre-imposed with a uniform axial magnetic field

Physics of Plasmas

Awe, Thomas J.; Owen, Albert C.; Gomez, Matthew R.; Hansen, Stephanie B.; Herrmann, Mark H.; Jones, Michael J.; Mckenney, John M.; Robertson, Grafton K.; Rochau, G.A.; Savage, Mark E.; Stygar, William A.; Jennings, Christopher A.; McBride, Ryan D.; Lamppa, Derek C.; Martin, Matthew; Rovang, Dean C.; Sinars, Daniel S.; Slutz, Stephen A.; Cuneo, M.E.

Abstract not provided.

Conceptual designs of 300-TW and 800-TW pulsed-power accelerators

Stygar, William A.; Fowler, William E.; Gomez, Matthew R.; Harmon, Roger L.; Herrmann, Mark H.; Huber, Dale L.; Hutsel, Brian T.; Bailey, James E.; Jones, Michael J.; Jones, Peter A.; Leckbee, Joshua L.; Lee, James R.; Lewis, Scot A.; Long, Finis W.; Lopez, Mike R.; Lucero, Diego J.; Matzen, M.K.; Mazarakis, Michael G.; McBride, Ryan D.; McKee, George R.; Nakhleh, Charles N.; Owen, Albert C.; Rochau, G.A.; Savage, Mark E.; Schwarz, Jens S.; Sefkow, Adam B.; Sinars, Daniel S.; Stoltzfus, Brian S.; Vesey, Roger A.; Wakeland, P.; Cuneo, M.E.; Flicker, Dawn G.; Focia, Ronald J.

Abstract not provided.

Integration of MHD load models with circuit representations the Z generator

Ampleford, David A.; Savage, Mark E.; Moore, James M.; Jones, Brent M.; McBride, Ryan D.; Bailey, James E.; Jones, Michael J.; Gomez, Matthew R.; Cuneo, M.E.; Nakhleh, Charles N.; Stygar, William A.

MHD models of imploding loads fielded on the Z accelerator are typically driven by reduced or simplified circuit representations of the generator. The performance of many of the imploding loads is critically dependent on the current and power delivered to them, so may be strongly influenced by the generators response to their implosion. Current losses diagnosed in the transmission lines approaching the load are further known to limit the energy delivery, while exhibiting some load dependence. Through comparing the convolute performance of a wide variety of short pulse Z loads we parameterize a convolute loss resistance applicable between different experiments. We incorporate this, and other current loss terms into a transmission line representation of the Z vacuum section. We then apply this model to study the current delivery to a wide variety of wire array and MagLif style liner loads.

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Architecture, implementation, and testing of a multiple-shell gas injection system for high current implosions on the Z accelerator

Review of Scientific Instruments

Strizic, Thomas S.; Johnson, Drew J.; Cunningham, Paul C.; Johns, Owen J.; Vigil, Marcelino V.; Jones, Brent M.; Ampleford, David A.; Savage, Mark E.; Cuneo, M.E.; Jones, Michael J.; Lamppa, Derek C.; Mckenney, John M.

Tests are ongoing to conduct ~20 MA z-pinch implosions on the Z accelerator at Sandia National Laboratory using Ar, Kr, and D2 gas puffs as the imploding loads. The relatively high cost of operations on a machine of this scale imposes stringent requirements on the functionality, reliability, and safety of gas puff hardware. Here we describe the development of a prototype gas puff system including the multiple-shell nozzles, electromagnetic drivers for each nozzle's valve, a UV pre-ionizer, and an inductive isolator to isolate the ~2.4 MV machine voltage pulse present at the gas load from the necessary electrical and fluid connections made to the puff system from outside the Z vacuum chamber. This paper shows how the assembly couples to the overall Z system and presents data taken to validate the functionality of the overall system.

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Pulsed-power driven inertial confinement fusion development at Sandia National Laboratories

Proposed for publication in 5th Special Issue of the IEEE Transactions on Plasma Science Z-Pinch Plasmas.

Cuneo, M.E.; Mazarakis, Michael G.; Lamppa, Derek C.; Kaye, Ronald J.; Nakhleh, Charles N.; Bailey, James E.; Hansen, Stephanie B.; McBride, Ryan D.; Herrmann, Mark H.; Lopez, A.; Peterson, Kyle J.; Ampleford, David A.; Jones, Michael J.; Savage, Mark E.; Jennings, Christopher A.; Martin, Matthew; Slutz, Stephen A.; Lemke, Raymond W.; Christenson, Peggy J.; Sweeney, Mary A.; Jones, Brent M.; Yu, Edmund Y.; McPherson, Leroy A.; Harding, Eric H.; Knapp, Patrick K.; Gomez, Matthew R.; Awe, Thomas J.; Stygar, William A.; Leeper, Ramon J.; Ruiz, Carlos L.; Chandler, Gordon A.; Mckenney, John M.; Owen, Albert C.; McKee, George R.; Matzen, M.K.; Leifeste, Gordon T.; Atherton, B.W.; Vesey, Roger A.; Smith, Ian C.; Geissel, Matthias G.; Rambo, Patrick K.; Sinars, Daniel S.; Sefkow, Adam B.; Rovang, Dean C.; Rochau, G.A.

Abstract not provided.

Total x-ray power improvement on recent wire array experiments on the Z machine

Jones, Michael J.; Ampleford, David A.; Cuneo, M.E.; Jennings, Christopher A.; Jones, Brent M.; Lopez, Mike R.; Rochau, G.A.; Savage, Mark E.

Recent experiments on the refurbished Z-machine were conducted using large diameter stainless steel arrays which produced x-ray powers of 260 TW. Follow-up experiments were then conducted utilizing tungsten wires with approximately the same total mass with the hypothesis that the total x-ray power would increase. On the large diameter tungsten experiments, the x-ray power averaged over 300 TW and the total x-ray energy was greater than 2MJ. Different analysis techniques for inferring the x-ray power will be described in detail.

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Investigation of radial wire arrays for inertial confinement fusion and radiation effects science

Ampleford, David A.; Jennings, Christopher A.; Cuneo, M.E.; McBride, Ryan D.; Sinars, Daniel S.; Jones, Brent M.; Coverdale, Christine A.; Jones, Michael J.

Radial wire arrays provide an alternative x-ray source for Z-pinch driven Inertial Confinement Fusion. These arrays, where wires are positioned radially outwards from a central cathode to a concentric anode, have the potential to drive a more compact ICF hohlraum. A number of experiments were performed on the 7MA Saturn Generator. These experiments studied a number of potential risks in scaling radial wire arrays up from the 1MA level, where they have been shown to provide similar x-ray outputs to larger diameter cylindrical arrays, to the higher current levels required for ICF. Data indicates that at 7MA radial arrays can obtain higher power densities than cylindrical wire arrays, so may be of use for x-ray driven ICF on future facilities. Even at the 7MA level, data using Saturn's short pulse mode indicates that a radial array should be able to drive a compact hohlraum to temperatures {approx}92eV, which may be of interest for opacity experiments. These arrays are also shown to have applications to jet production for laboratory astrophysics. MHD simulations require additional physics to match the observed behavior.

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Compact wire array sources: power scaling and implosion physics

Jones, Brent M.; Cuneo, M.E.; Ampleford, David A.; Coverdale, Christine A.; Vesey, Roger A.; Jones, Michael J.

A series of ten shots were performed on the Saturn generator in short pulse mode in order to study planar and small-diameter cylindrical tungsten wire arrays at {approx}5 MA current levels and 50-60 ns implosion times as candidates for compact z-pinch radiation sources. A new vacuum hohlraum configuration has been proposed in which multiple z pinches are driven in parallel by a pulsed power generator. Each pinch resides in a separate return current cage, serving also as a primary hohlraum. A collection of such radiation sources surround a compact secondary hohlraum, which may potentially provide an attractive Planckian radiation source or house an inertial confinement fusion fuel capsule. Prior to studying this concept experimentally or numerically, advanced compact wire array loads must be developed and their scaling behavior understood. The 2008 Saturn planar array experiments extend the data set presented in Ref. [1], which studied planar arrays at {approx}3 MA, 100 ns in Saturn long pulse mode. Planar wire array power and yield scaling studies now include current levels directly applicable to multi-pinch experiments that could be performed on the 25 MA Z machine. A maximum total x-ray power of 15 TW (250 kJ in the main pulse, 330 kJ total yield) was observed with a 12-mm-wide planar array at 5.3 MA, 52 ns. The full data set indicates power scaling that is sub-quadratic with load current, while total and main pulse yields are closer to quadratic; these trends are similar to observations of compact cylindrical tungsten arrays on Z. We continue the investigation of energy coupling in these short pulse Saturn experiments using zero-dimensional-type implosion modeling and pinhole imaging, indicating 16 cm/?s implosion velocity in a 12-mm-wide array. The same phenomena of significant trailing mass and evidence for resistive heating are observed at 5 MA as at 3 MA. 17 kJ of Al K-shell radiation was obtained in one Al planar array fielded at 5.5 MA, 57 ns and we compare this to cylindrical array results in the context of a K-shell yield scaling model. We have also performed an initial study of compact 3 mm diameter cylindrical wire arrays, which are alternate candidates for a multi-pinch vacuum hohlraum concept. These massive 3.4 and 6 mg/cm loads may have been impacted by opacity, producing a maximum x-ray power of 7 TW at 4.5 MA, 45 ns. Future research directions in compact x-ray sources are discussed.

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Planar wire array dynamics and radiation scaling at multi-MA levels on the Saturn pulsed power generator

Jones, Brent M.; Cuneo, M.E.; Ampleford, David A.; Coverdale, Christine A.; Vesey, Roger A.; Jones, Michael J.

Planar wire arrays are studied at 3-6 MA on the Saturn pulsed power generator as potential drivers of compact hohlraums for inertial confinement fusion studies. Comparison with zero-dimensional modeling suggests that there is significant trailing mass. The modeled energy coupled from the generator cannot generally explain the energy in the main x-ray pulse. Preliminary comparison at 1-6 MA indicates sub-quadratic scaling of x-ray power in a manner similar to compact cylindrical wire arrays. Time-resolved pinhole images are used to study the implosion dynamics.

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Atmospheric electromagnetic pulse propagation effects from thick targets in a terawatt laser target chamber

Applied Optics

Adams, Richard G.; Jones, Michael J.

Generation and effects of atmospherically propagated electromagnetic pulses (EMPs) initiated by photoelectrons ejected by the high density and temperature target surface plasmas from multiterawatt laser pulses are analyzed. These laser radiation pulse interactions can significantly increase noise levels, thereby obscuring data (sometimes totally) and may even damage sensitive probe and detection instrumentation. Noise effects from high energy density (approximately multiterawatt) laser pulses (~300–400 ps pulse widths) interacting with thick (~1 mm) metallic and dielectric solid targets and dielectric–metallic powder mixtures are interpreted as transient resonance radiation associated with surface charge fluctuations on the target chamber that functions as a radiating antenna. Effective solutions that minimize atmospheric EMP effects on internal and proximate electronic and electro-optical equipment external to the system based on systematic measurements using Moebius loop antennas, interpretations of signal periodicities, and dissipation indicators determining transient noise origin characteristics from target emissions are described. Analytic models for the effect of target chamber resonances and associated noise current and temperature in a probe diode laser are described.

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1- and 2-frame monochromatic x-ray imaging of NIF-like capsules on Z and future higher-energy higher-resolution 2- & 4-frame x-radiography plans for ZR

Bennett, Guy R.; Campbell, David V.; Claus, Liam D.; Foresi, James S.; Johnson, Drew J.; Jones, Michael J.; Keller, Keith L.; Leifeste, Gordon T.; McPherson, Leroy A.; Mulville, Thomas D.; Neely, Kelly A.; Sinars, Daniel S.; Herrmann, Mark H.; Rambo, Patrick K.; Rovang, Dean C.; Ruggles, Larry R.; Simpson, Walter W.; Speas, Christopher S.; Wenger, D.F.; Smith, Ian C.; Cuneo, M.E.; Adams, Richard G.; Atherton, B.W.; Barnard, Wilson J.; Beutler, David E.; Burr, Robert A.

Abstract not provided.

82 Results
82 Results