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20 results on '"A. V. Hamza"'

1. First Liquid Layer Inertial Confinement Fusion Implosions at the National Ignition Facility

Author

Nathan Meezan, T. Braun, B. J. Kozioziemski, A. V. Hamza, L. F. Berzak Hopkins, Paul A. Bradley, Monika M. Biener, R. J. Leeper, C. Kong, A. Nikroo, George A. Kyrala, Doug Wilson, C. F. Walters, S. A. Yi, Hans W. Herrmann, Robert R. Peterson, Steven H. Batha, R. C. Shah, J. Biener, R. E. Olson, J. D. Sater, Lin Yin, J. W. Crippen, John Kline, Brian Haines, and Alex Zylstra

Subjects
Materials science, Nuclear engineering, General Physics and Astronomy, Sense (electronics), Nova (laser), Radiation, 01 natural sciences, 010305 fluids & plasmas, law.invention, Ignition system, Deuterium, law, 0103 physical sciences, Neutron, 010306 general physics, National Ignition Facility, Inertial confinement fusion
Abstract

The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D_{2} and DT layer inertial confinement fusion (ICF) implosions that can access a low-to-moderate hot-spot convergence ratio (12CR25). Previous ICF experiments at the NIF utilized high convergence (CR30) DT ice layer implosions. Although high CR is desirable in an idealized 1D sense, it amplifies the deleterious effects of asymmetries. To date, these asymmetries prevented the achievement of ignition at the NIF and are the major cause of simulation-experiment disagreement. In the initial liquid layer experiments, high neutron yields were achieved with CRs of 12-17, and the hot-spot formation is well understood, demonstrated by a good agreement between the experimental data and the radiation hydrodynamic simulations. These initial experiments open a new NIF experimental capability that provides an opportunity to explore the relationship between hot-spot convergence ratio and the robustness of hot-spot formation during ICF implosions.

Published
2016

2. First High-Convergence Cryogenic Implosion in a Near-Vacuum Hohlraum

Author

J. D. Moody, Michael Stadermann, Andrew MacPhee, George A. Kyrala, E. Woerner, J. A. Church, D. A. Callahan, Gary Grim, Daniel Sayre, Abbas Nikroo, T. Ma, Wolfgang Stoeffl, Laurent Divol, James Ross, L. F. Berzak Hopkins, D. Hoover, Mark Eckart, Laura Robin Benedetti, Robert Hatarik, M. Gatu Johnson, Richard Town, A. J. Mackinnon, Shahab Khan, Hans W. Herrmann, Frank E. Merrill, S. M. Sepke, J. A. Caggiano, Jeremy Kroll, Harry Robey, James McNaney, Rebecca Dylla-Spears, C. B. Yeamans, A. V. Hamza, H. Huang, E. P. Hartouni, Matthias Hohenberger, David C. Clark, J. D. Kilkenny, Carl Wilde, D. H. Edgell, Darwin Ho, P. K. Patel, M. J. Edwards, Tilo Döppner, Art Pak, Nobuhiko Izumi, Denise Hinkel, Cliff Thomas, Jose Milovich, R. M. Bionta, Joseph Ralph, Otto Landen, B. E. Yoxall, Michael Schneider, Nathan Meezan, J. Sater, S. Le Pape, Petr Volegov, N. Guler, C. J. Cerjan, David N. Fittinghoff, C. Wild, D. K. Bradley, B. J. Kozioziemski, J. E. Field, O. S. Jones, E. J. Bond, Juergen Biener, S. W. Haan, W. W. Hsing, and J. R. Rygg

Subjects
Physics, business.industry, General Physics and Astronomy, Implosion, Plasma, Laser, Symmetry (physics), Pulse (physics), law.invention, Nuclear physics, Optics, Physics::Plasma Physics, Hohlraum, law, Neutron, National Ignition Facility, business
Abstract

Recent experiments on the National Ignition Facility [M. J. Edwards et al., Phys. Plasmas 20, 070501 (2013)] demonstrate that utilizing a near-vacuum hohlraum (low pressure gas-filled) is a viable option for high convergence cryogenic deuterium-tritium (DT) layered capsule implosions. This is made possible by using a dense ablator (high-density carbon), which shortens the drive duration needed to achieve high convergence: a measured 40% higher hohlraum efficiency than typical gas-filled hohlraums, which requires less laser energy going into the hohlraum, and an observed better symmetry control than anticipated by standard hydrodynamics simulations. The first series of near-vacuum hohlraum experiments culminated in a 6.8 ns, 1.2 MJ laser pulse driving a 2-shock, high adiabat (α ~ 3.5) cryogenic DT layered high density carbon capsule. This resulted in one of the best performances so far on the NIF relative to laser energy, with a measured primary neutron yield of 1.8 X 10¹⁵ neutrons, with 20% calculated alpha heating at convergence ~27X.

Published
2015

3. First Measurements of Hydrodynamic Instability Growth in Indirectly Driven Implosions at Ignition-Relevant Conditions on the National Ignition Facility

Author

Otto Landen, Daniel Casey, Klaus Widmann, V. A. Smalyuk, Daniel S. Clark, A. V. Hamza, Alastair Moore, Kumar Raman, Abbas Nikroo, M. J. Edwards, Omar Hurricane, S. V. Weber, Jeremy Kroll, Harry Robey, Bruce Remington, W. W. Hsing, Larry L. Peterson, J. D. Kilkenny, S. W. Haan, and D. Hoover

Subjects
Ignition system, Nuclear physics, Physics::Plasma Physics, law, Nuclear engineering, Physics::Medical Physics, General Physics and Astronomy, Environmental science, National Ignition Facility, Instability, law.invention
Abstract

Ignition experiments have shown an anomalous susceptibility to hydrodynamic instability growth. To help understand these results, the first hydrodynamic instability growth measurements in indirectly driven implosions on the National Ignition Facility were performed at ignition conditions with peak radiation temperatures up to ∼300 eV. Plastic capsules with two-dimensional preimposed, sinusoidal outer surface modulations of initial wavelengths of 240 (corresponding to a Legendre mode number of 30), 120 (mode 60), and 80 μm (mode 90) were imploded by using actual low-adiabat ignition laser pulses. The measured growth was in excellent agreement, validating 2D hydra simulations for the most dangerous modes in the acceleration phase. These results reinforce confidence in the predictive capability of calculations that are paramount to illuminating the path toward ignition.

Published
2014

4. Deposition of Potential Energy in Solids by Slow, Highly Charged Ions

Author

Thomas Schenkel, T. R. Niedermayr, M. Hattass, D. H. Schneider, J. W. McDonald, A. V. Hamza, A. V. Barnes, G. A. Machicoane, and M. W. Newman

Subjects
Physics, Ion implantation, General Physics and Astronomy, Silicon detector, Atomic physics, Ionization energy, Potential energy, Deposition (law), Ion, Semiconductor detector
Abstract

We have measured the deposition of potential energy of slow $(\ensuremath{\sim}6\ifmmode\times\else\texttimes\fi{}{10}^{5}\mathrm{m}/\mathrm{s})$, highly charged ions in solids with an ion implanted silicon detector. A large fraction (about $35%$ or 60 keV) of the potential energy dissipated by ${\mathrm{Au}}^{69+}$ ions can be traced in electronic excitations deep $(g50\mathrm{nm})$ inside the solid. In contrast, only about $10%$ of the potential energy has been accounted for in measurements of emitted secondary particles.

Published
1999

5. Charge Equilibration Time of Slow, Highly Charged Ions in Solids

Author

Alex V. Hamza, A. V. Barnes, T. R. Niedermayr, Thomas Schenkel, J. W. McDonald, G. A. Machicoane, D. H. Schneider, M. W. Newman, and M. Hattass

Subjects
Materials science, Auger effect, General Physics and Astronomy, Non-equilibrium thermodynamics, chemistry.chemical_element, Charge (physics), Ion, symbols.namesake, Xenon, chemistry, Solid matter, symbols, Atomic physics, Carbon, FOIL method
Abstract

We report observations of nonequilibrium charge state distributions of slow, highly charged (33+{le} q{le}75+) ions after transmission of thin carbon foils. Charge equilibration times are determined directly from the dependencies of exit charge states on projectile velocity (0.5{times}10{sup 6}{lt}v{lt}10{sup 6} m/s) and foil thickness (5{endash}10thinspthinspnm). Ions like Xe{sup 44+} and Au{sup 68+} are found to equilibrate inside of solid matter in a time of only 7thinspthinspfs. {copyright} {ital 1999} {ital The American Physical Society}

Published
1999

6. Ablation of GaAs by Intense, Ultrafast Electronic Excitation from Highly Charged Ions

Author

D. H. Schneider, Barney Lee Doyle, J. C. Banks, A. V. Barnes, Alex V. Hamza, and Thomas Schenkel

Subjects
Physics, business.industry, General Physics and Astronomy, Charge (physics), Potential energy, Ion, Semiconductor, Physics::Plasma Physics, Sputtering, Secondary emission, Femtosecond, Physics::Atomic and Molecular Clusters, Atomic physics, business, Excitation
Abstract

We have measured total ablation rates and secondary ion yields from undoped GaAs(100) interacting with slow $(v\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}6.6\ifmmode\times\else\texttimes\fi{}{10}^{5}\mathrm{m}/\mathrm{s})$, very highly charged ions. Ablation rates increase strongly as a function of projectile charge. Some 1400 target atoms are removed when a single ${\mathrm{Th}}^{70+}$ ion deposits a potential energy of 152.6 keV within a few femtoseconds into a nanometer-sized target volume. We discuss models for ablation of semiconductors by intense, ultrafast electronic excitation.

Published
1998

7. Synergy of Electronic Excitations and Elastic Collision Spikes in Sputtering of Heavy Metal Oxides

Author

Alex V. Hamza, J. C. Banks, A. V. Barnes, Barney Lee Doyle, D. H. Schneider, and Thomas Schenkel

Subjects
Elastic scattering, Materials science, Projectile, General Physics and Astronomy, Electronic structure, Elastic collision, Ion, chemistry.chemical_compound, chemistry, Physics::Plasma Physics, Sputtering, Secondary emission, Uranium oxide, Atomic physics, Nuclear Experiment
Abstract

The emission of secondary ions and neutrals from uranium oxide has been measured for impact of highly charged, heavy ions. Total ablation rates and secondary ion yields increase strongly with projectile charge. The dependencies on projectile charge $(16lql70)$, impact energy $(10\mathrm{keV}l{E}_{\mathrm{kin}}l1\mathrm{MeV})$, and projectile mass of secondary ion yields demonstrate the presence of an interaction regime where electronic excitation by charge neutralization and elastic collision spikes combine synergistically.

Published
1998

8. Charge State Dependent Energy Loss of Slow Heavy Ions in Solids

Author

Klaus Bethge, D. H. Schneider, Alex V. Hamza, Thomas Schenkel, Horst Schmidt-Böcking, M. A. Briere, and A. V. Barnes

Subjects
Physics, symbols.namesake, Range (particle radiation), Energy loss, State dependent, symbols, General Physics and Astronomy, Charge (physics), Atomic physics, Kinetic energy, Bohr model, Ion
Abstract

The loss of kinetic energy of slow $({v\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.3v}_{\mathrm{Bohr}})$ ions transmitted through thin carbon foils has been measured as a function of projectile charge state in the range from $q\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}3+$ for oxygen to $q\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}69+$ for gold ions. For the first time, charge state dependent energy loss enhancements have been observed for ${\mathrm{Xe}}^{q+}$ and ${\mathrm{Au}}^{q+}$ at $q\ensuremath{\ge}40+$, indicating strong preequilibrium contributions to the energy loss of slow, highly charged ions in solids.

Published
1997

9. Hot-Spot Mix in Ignition-Scale Inertial Confinement Fusion Targets

Author

V. A. Smalyuk, Richard Town, O. S. Jones, Roberto Mancini, S. H. Glenzer, Nathan Meezan, J. D. Kilkenny, Joseph J. MacFarlane, A. V. Hamza, P. T. Springer, Howard A. Scott, Sean Regan, S. N. Dixit, T. Ma, Melissa Edwards, A. Nikroo, David R. Farley, Joseph Ralph, Otto Landen, R. L. McCrory, S. M. Glenn, T. C. Sangster, K. B. Fournier, Tilo Döppner, G. A. Kyrala, S. W. Haan, Damien Hicks, D. D. Meyerhofer, Debra Callahan, D. K. Bradley, Gilbert Collins, Nobuhiko Izumi, Igor Golovkin, John Kline, H.-S. Park, A. J. Mackinnon, Reuben Epstein, Bruce Remington, B. A. Hammel, M. A. Barrios, L. J. Suter, and C. J. Cerjan

Subjects
Materials science, Quantitative Biology::Neurons and Cognition, Doping, Mixing (process engineering), General Physics and Astronomy, Hot spot (veterinary medicine), law.invention, Ignition system, Physics::Plasma Physics, law, Neutron, Atomic physics, National Ignition Facility, Spectroscopy, Inertial confinement fusion
Abstract

Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. As a result, low neutron yields and hot-spot mix mass between 34(–13,+50) ng and 4000(–2970,+17 160) ng are observed.

Published
2013

10. Measurements of an ablator-gas atomic mix in indirectly driven implosions at the National Ignition Facility

Author

M. A. Barrios, J. A. Caggiano, Bruce Remington, Abbas Nikroo, John Kline, J. Pino, Gary Grim, J. P. Knauer, S. V. Weber, D. L. Bleuel, T. G. Parham, R. D. Petrasso, R. Tommasini, C. J. Cerjan, M. Mintz, Laura Robin Benedetti, Alastair Moore, D. K. Bradley, Richard Town, Shahab Khan, Daniel S. Clark, J. D. Kilkenny, Doug Wilson, A. V. Hamza, D. A. Callahan, S. W. Haan, T. Ma, Johan Frenje, D. H. Edgell, Maria Gatu-Johnson, Robert Hatarik, Daniel Sayre, W. W. Hsing, Marilyn Schneider, James McNaney, S. M. Glenn, Nobuhiko Izumi, M. J. Edwards, Daniel Casey, Art Pak, D. Rowley, Robert Tipton, C. B. Yeamans, Klaus Widmann, Otto Landen, V. A. Smalyuk, and V. Y. Glebov

Subjects
Nuclear engineering, General Physics and Astronomy, Environmental science, National laboratory, National Ignition Facility
Abstract

We present the first results from an experimental campaign to measure the atomic ablator-gas mix in the deceleration phase of gas-filled capsule implosions on the National Ignition Facility. Plastic capsules containing CD layers were filled with tritium gas; as the reactants are initially separated, DT fusion yield provides a direct measure of the atomic mix of ablator into the hot spot gas. Capsules were imploded with x rays generated in hohlraums with peak radiation temperatures of ∼294 eV. While the TT fusion reaction probes conditions in the central part (core) of the implosion hot spot, the DT reaction probes a mixed region on the outer part of the hot spot near the ablator-hot-spot interface. Experimental data were used to develop and validate the atomic-mix model used in two-dimensional simulations.

Published
2013

11. Measurement of high-pressure shock waves in cryogenic deuterium-tritium ice layered capsule implosions on NIF

Author

J. D. Moody, L. J. Atherton, Mark W. Bowers, B. M. Van Wonterghem, J. E. Ralph, Melissa Edwards, Otto Landen, G. Frieders, D. M. Holunga, B. K. F. Young, K. G. Krauter, James Ross, Suhas Bhandarkar, A. V. Hamza, B Dzenitis, Evan Mapoles, Peter M. Celliers, J. D. Sater, David Strozzi, B. E. Yoxall, Rebecca Dylla-Spears, C. F. Walters, T. G. Parham, T. R. Boehly, B. J. Kozioziemski, B. J. Haid, L. F. Berzak Hopkins, Harry Robey, G. Ross, and S. Le Pape

Subjects
Shock wave, Materials science, Deuterium, Physics::Plasma Physics, High pressure, Compressibility, General Physics and Astronomy, Tritium, Mechanics, Experimental validation, National Ignition Facility, Inertial confinement fusion
Abstract

The first measurements of multiple, high-pressure shock waves in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility have been performed. The strength and relative timing of these shocks must be adjusted to very high precision in order to keep the DT fuel entropy low and compressibility high. All previous measurements of shock timing in inertial confinement fusion implosions [T. R. Boehly et al., Phys. Rev. Lett. 106, 195005 (2011), H. F. Robey et al., Phys. Rev. Lett. 108, 215004 (2012)] have been performed in surrogate targets, where the solid DT ice shell and central DT gas regions were replaced with a continuous liquid deuterium (D2) fill. This report presents the first experimental validation of the assumptions underlying this surrogate technique.

Published
2013

12. Precision Shock Tuning on the National Ignition Facility

Author

C. A. Haynam, J. D. Kilkenny, Jon Eggert, Tilo Döppner, Jose Milovich, E. L. Dewald, David R. Farley, Edward I. Moses, O. S. Jones, Peter M. Celliers, C. F. Walters, C. C. Widmayer, Kenneth S. Jancaitis, T. N. Malsbury, J. B. Horner, Jeremy Kroll, T. G. Parham, Harry Robey, T. R. Boehly, M. Gatu Johnson, John Kline, Damien Hicks, E T Alger, E. G. Dzenitis, C. Choate, E. M. Giraldez, J. A. Caggiano, Marilyn Schneider, D. Trummer, D. D. Meyerhofer, A. J. Mackinnon, J. D. Lindl, K. A. Moreno, Carlos E. Castro, D. H. Munro, D. M. Holunga, S. W. Haan, B. K. Young, K. G. Krauter, Otto Landen, B. J. MacGowan, Klaus Widmann, D. T. Casey, L. V. Berzins, B. M. Van Wonterghem, S. Le Pape, H. Chandrasekaran, J. A. Frenje, S. N. Dixit, David C. Clark, F. H. Séguin, J. Atherton, B. Haid, A. V. Hamza, Melissa Edwards, Mark W. Bowers, A. Nikroo, B. Burr, S. J. Brereton, Brian Spears, K. N. LaFortune, M. J. Shaw, K. R. Coffee, Harry B. Radousky, Siegfried Glenzer, Richard Town, J. D. Moody, Suhas Bhandarkar, J. P. Knauer, and S. Azevedo

Subjects
Shock wave, Physics, Ignition system, Optical diagnostics, Computer simulation, law, Nuclear engineering, General Physics and Astronomy, Area density, Plasma, Fusion power, National Ignition Facility, law.invention
Abstract

Ignition implosions on the National Ignition Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] are underway with the goal of compressing deuterium-tritium fuel to a sufficiently high areal density (ρR) to sustain a self-propagating burn wave required for fusion power gain greater than unity. These implosions are driven with a very carefully tailored sequence of four shock waves that must be timed to very high precision to keep the fuel entropy and adiabat low and ρR high. The first series of precision tuning experiments on the National Ignition Facility, which use optical diagnostics to directly measure the strength and timing of all four shocks inside a hohlraum-driven, cryogenic liquid-deuterium-filled capsule interior have now been performed. The results of these experiments are presented demonstrating a significant decrease in adiabat over previously untuned implosions. The impact of the improved shock timing is confirmed in related deuterium-tritium layered capsule implosions, which show the highest fuel compression (ρR~1.0 g/cm(2)) measured to date, exceeding the previous record [V. Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)] by more than a factor of 3. The experiments also clearly reveal an issue with the 4th shock velocity, which is observed to be 20% slower than predictions from numerical simulation.

Published
2012

13. Assembly of High-Areal-Density Deuterium-Tritium Fuel from Indirectly Driven Cryogenic Implosions

Author

E. Giraldez, K. N. La Fortune, Mark W. Bowers, David R. Farley, Steve Glenn, W. H. Courdin, C. A. Thomas, P. S. Datte, K. M. Knittel, B. Haid, C. Stoeckl, K. Moreno, James Knauer, Edward I. Moses, S. W. Haan, N. Guler, J. J. Klingman, P. M. Celliers, P. T. Springer, B. J. Kozioziemski, H. F. Robey, J. D. Sater, A. J. MacKinnon, S. Weaver, N. E. Palmer, R. Bionta, M. A. Barrios, S. G. Brass, L. V. Berzins, Gordon A. Chandler, G. Frieders, Chris Haynam, E. P. Hartouni, Gary Wayne Cooper, G. N. McHalle, Marilyn Schneider, Chimpén Ruiz, Abbas Nikroo, R. J. Fortner, Hans Rinderknecht, Joseph Ralph, N. Simanovskaia, Michael J. Moran, S. J. Cohen, Pierre Michel, R. J. Leeper, Ogden Jones, G. LaCaille, T. G. Parham, R. Benedetti, R. P. J. Town, Eduard Dewald, P. Di Nicola, D. H. Munro, S. C. Burkhart, L. J. Atherton, Maria Gatu Johnson, R. W. Patterson, Hans W. Herrmann, A. Zylestra, Mahalia Jackson, John Lindl, David K. Bradley, Steven Weber, E. S. Palma, James McNaney, John Kline, M. J. Shaw, S. N. Dixit, T. A. Land, Daniel Casey, Gilbert Collins, P. W. McKenty, Paul J. Wegner, Brian Spears, C. Marshall, K. Widmann, D. G. Mathisen, Vladimir Glebov, R. E. Olson, Alex V. Hamza, R. F. Burr, Frank E. Merrill, Owen B. Drury, M. Hermann, Sean Regan, Rebecca Dylla-Spears, C. Clay Widmayer, Nathan Meezan, J. R. Kimbrough, G. Heestand, R. K. Kirkwood, Daniel Clark, R. Saunders, B.M. VanWonterghem, R. Lowe-Webb, K.S. Jancaitis, Perry M. Bell, Pamela K. Whitman, J. A. Caggiano, Damien Hicks, Charles Cerjan, R. J. Wallace, B. K. Young, P. A. Arnold, R. Tommasini, Robert L. Kauffman, A. G. Nelson, E. J. Bond, Alastair Moore, J. R. Cox, Steven H. Batha, Siegfried Glenzer, Bruce Hammel, J Eggert, B. Felker, Laurent Divol, D. A. Callahan, R. B. Ehrlich, Andrew MacPhee, Johan Frenje, D. H. Schneider, Evan Mapoles, Charles D. Orth, R. Prasad, Jose Milovich, K. G. Krauter, G. Gururangan, R. D. Wood, R. C. Ashabranner, E. G. Dzenitis, G. W. Krauter, John M. Dzenitis, J. P. Holder, Prav Patel, B. J. MacGowan, D. N. Fittinghoff, L. J. Lagin, Nobuhiko Izumi, J. M. Dinicola, D. L. Blueuel, Stephan Friedrich, G. Ross, D. H. Edgell, C. F. Walters, James E. Fair, J. D. Kilkenny, Craig Sangster, John Moody, Mary Sue Richardson, R. A. Zacharias, Robert Hatarik, D. Latray, David C. Eder, O. L. Landen, M. J. Eckart, T. Kohut, R. D. Petrasso, J. D. Salmonsen, G. A. Kyrala, Gary Grim, K. D. Hahn, Steve Hatchett, T. Ma, Suhas Bhandarkar, Wolfgang Stoeffl, G Brunton, L. J. Suter, Thomas Boehly, L. A. Bernstein, M. J. Edwards, Tilo Döppner, David Larson, S. Lepape, Dan Kalantar, G. Erbert, and Doug Wilson

Subjects
Ignition system, Materials science, Deuterium, Hohlraum, law, Nuclear engineering, General Physics and Astronomy, Implosion, Neutron, Area density, Radius, National Ignition Facility, law.invention
Abstract

The National Ignition Facility has been used to compress deuterium-tritium to an average areal density of ~1.0±0.1 g cm(-2), which is 67% of the ignition requirement. These conditions were obtained using 192 laser beams with total energy of 1-1.6 MJ and peak power up to 420 TW to create a hohlraum drive with a shaped power profile, peaking at a soft x-ray radiation temperature of 275-300 eV. This pulse delivered a series of shocks that compressed a capsule containing cryogenic deuterium-tritium to a radius of 25-35 μm. Neutron images of the implosion were used to estimate a fuel density of 500-800 g cm(-3).

Published
2012

14. Publisher’s Note: Demonstration of Ignition Radiation Temperatures in Indirect-Drive Inertial Confinement Fusion Hohlraums [Phys. Rev. Lett.106, 085004 (2011)]

Author

B. L. Pepmeier, D. L. Hodtwalker, B. V. Beeman, J. D. Hollis, P. S. Yang, S. A. Silva, M. J. Richardson, J. L. Vaher, K. Gu, B. N. M. Balaoing, J. E. Krammen, P. J. van Arsdall, N. I. Spafford, M. M. Montoya, M. A. Jackson, F. W. Chambers, J. Grippen, M. Neto, P. H. Gschweng, J. D. Moody, C. A. Haynam, S. Huber, A. P. Ludwigsen, E T Alger, G. M. Curnow, J. Watkins, J. C. Ellefson, S. Sailors, B. McHale, L. F. Alvarez, H. Chandrasekaran, T. E. Mills, Cliff Thomas, P. L. Stratton, R. Zacharias, J. D. Hitchcock, P. M. Bell, J. F. Meeker, E. L. Dewald, R. K. Butlin, T. G. Stone, K. P. Youngblood, Mark W. Bowers, M. Runkel, E. Padilla, M. W. Owens, S. S. Alvarez, J. G. Soto, L. J. Atherton, J. McBride, W. A. Reid, M. Y. Mauvais, G. Heestand, O. D. Edwards, S. W. Lane, A. A. Marsh, T. N. Malsbury, S. R. Robison, P. M. Danforth, J. D. Kilkenny, J. A. Baltz, M. J. Dailey, R. C. Montesanti, J. D. Driscoll, B. J. MacGowan, M. K. Shiflett, Donald F. Browning, F. J. Lopez, C. R. Gibson, F. E. Wade, R. Darbee, Mark R. Hermann, B Fishler, Y. Chen, Edward I. Moses, G. A. Kyrala, R. D. Demaret, J. G. Lown, M. D. Magat, S. Azevedo, G. Erbert, R. K. Kirkwood, K. Charron, Harry B. Radousky, R. T. Shelton, M. E. Sheldrick, R. R. Lyons, C. T. Warren, Paul J. Wegner, P. V. Amick, B. Johnson, G. Hermes, K. M. Morriston, G. A. Keating, T. G. Parham, K. S. Andersson, G. Ross, C. H. Ellerbee, D. A. Callahan, A. S. Rivenes, C. B. Foxworthy, M. C. Johnson, R. Miramontes-Ortiz, P. T. Springer, P. Datte, T. Kohut, J. Neumann, A. J. van Prooyen, C. Thai, M. J. Edwards, K. Work, Tilo Döppner, K. D. Pletcher, G. Frieder, D. S. Hey, T. Ma, A. J. Churby, I. L. Maslennikov, M. C. Witte, Siegfried Glenzer, G. J. Mauger, B. E. Smith, Suhas Bhandarkar, S. C. Burkhart, Joseph Ralph, T. J. Clancy, E. Ng, Thomas J. Johnson, K. L. Griffin, Rolf K. Reed, J. Braucht, R. Rinnert, J.M.Fisher, J. M. Di Nicola, N. Lao, A. L. Throop, S. Hunter, R. L. Rampke, Nathan Meezan, D. A. Barker, Otto Landen, Mark Eckart, M. A. Bergonia, K. N. La Fortune, J. R. Kimbrough, T. R. Huppler, R. A. London, G. L. Tietbohl, J. J. Rhodes, Christoph Niemann, Richard Town, W. J. Fabyan, Joseph W. Carlson, K. M. Skulina, G. Pavel, T. W. Phillips, B. D. Cline, R. G. Hartley, R. J. Wallace, T. L. Lee, C. C. Widmayer, Steven H. Langer, L. F. Finnie, J. Morris, G. T. Villanueva, S. W. Kramer, L. K. Smith, J. W. Florio, D. Pigg, J. L. Vickers, A. S. Runtal, F. E. Coffield, D. G. Cocherell, Pamela K. Whitman, S. Le Pape, Michael Stadermann, E. A. Stout, J. Liebman, V. K. Lakamsani, D. K. Bradley, J. A. Borgman, D. G. Mathisen, M. D. Vergino, P. A. Arnold, Kenneth S. Jancaitis, M. D. Rosen, Jeremy Kroll, J. Dugorepec, M. F. Swisher, J. M. Tillman, D. Pendleton, D. E. Speck, E. Mertens, K. King, Q. M. Ngo, G. Bardsley, E. A. Tekle, R. Costa, Robert L. Kauffman, D. T. Boyle, J. E. Hamblen, D. M. Lord, B. L. Lechleiter, M.S.Hutton, T. Fung, J. R. Schaffer, E. M. Giraldez, S. N. Dixit, John R. Celeste, Laurent Divol, L. C. Clowdus, B. K. Young, D. Trummer, H. Gonzales, B. P. Golick, D. T. Maloy, J. P. Holder, Wendi Sweet, S. R. Marshall, G. J. Edwards, Sally Andrews, G. A. Deis, L. J. Bernardez, D. Larson, L. L. Silva, A. McGrew, G Brunton, S. M. Glenn, Alexander Thomas, Jay D. Salmonson, R. E. Olson, C. M. Estes, Wade H. Williams, K. G. Koka, A. I. Barnes, M. A. Vitalich, A. Y. Chakicherla, J. L. Reynolds, B. Haid, J. T. Salmon, L. V. Berzins, O. S. Jones, B. A. Wilson, M. G. Miller, L. M. Kegelmeyer, Mark J. Schmitt, E. J. Bond, D. R. Bopp, G. T. Lau, N. W. Lum, Kevin S. White, J. T. Fink, D. R. Hart, Marilyn Schneider, F. Stanley, D. B. Dobson, F. Barbosa, L. J. Suter, M. Shor, A. V. Hamza, D. L. Hardy, T. McCarville, D. L. Hipple, C. J. Roberts, P. W. Edwards, R. W. Patterson, Ronald B. Robinson, J. B. Tassano, B. S. Raimondi, S. R. Hahn, G. Gururangan, P. C. Dupuy, R. L. Hibbard, J. R. Nelson, D. A. Smauley, M. J. Fischer, J. H. Kamperschroer, G. Holtmeier, Andrew MacPhee, E. A. Williams, P. A. Adams, K. G. Krauter, Jose Milovich, Stephen P. Vernon, L. J. Lagin, G. N. Gawinski, J. S. Taylor, G. Antonini, M. P. Johnston, M. C. Valadez, M. A. Weingart, S. L. Edson, John Kline, S. M. Gross, A. Baron, J. D. Tappero, N. L. Orsi, J. A. Davis, J. Klingmann, N. J. Cahayag, Carlos E. Castro, J. D. Lindl, A. T. Rivera, L. R. Belk, S. L. Kenitzer, J. Duncan, K. E. Burns, A. L. Solomon, R. C. Bettenhausen, B. M. Van Wonterghem, S. P. Rogers, R G Beeler, D. Latray, H. K. Loey, T. M. Pannell, B. Felker, T. Frazier, V. Rekow, P. G. Zapata, A. J. Mackinnon, R. W. Carey, P. S. Cardinale, J. Jackson, John Moody, S. Burns, L. Willis, J. L. Bragg, D. E. Petersen, E. G. Dzenitis, D. R. Jedlovec, J. R. Cox, D. E. Hinkel, J. A. Robinson, John R. Bower, E. O. Vergel de Dios, B. A. Hammel, L. M. Burrows, Daniel H. Kalantar, Klaus Widmann, M. J. Christensen, R. Prasad, A. L. Warrick, K. Wilhelmsen, R. Chapman, O. R. Rodriguez, A. W. Huey, B. L. Olejniczak, G. W. Krauter, S. W. Haan, Claire Bishop, H. Zhang, J. B. Alfonso, J. H. Truong, S. Weaver, K. S. Segraves, S. Sommer, J. C. Bell, Y. Lee, S. Shiromizu, R. Saunders, R. N. Fallejo, K. Piston, J. Wen, R. M. Marquez, K. L. Tribbey, S. A. Gonzales, P. Di Nicola, R. M. Franks, A. Nikroo, G. A. Bowers, J. B. McCloud, K. A. Moreno, Nobuhiko Izumi, S. F. Locke, S. A. Vonhof, E. F. Wilson, M. D. Finney, D. P. Atkinson, Damien Hicks, R. Lowe-Webb, R. A. Sacks, B. Riordan, M. Fedorov, A. B. Langdon, Z. Alherz, D. N. Hulsey, E. K. Krieger, S. J. Cohen, T. M. Schindler, B. Burr, J. S. Merill, C. Powell, Pierre Michel, J. S. Zielinski, M. J. Gonzales, C. Marshall, Richard Berger, C. Chan, J. Li, S. L. Townsend, L. Auyang, F. A. Penko, A. D. Casey, C. Chang, D. L. Brinkerhoff, K. M. Knittel, R. J. Strauser, G. Markham, and M. J. Shaw

Subjects
Nuclear physics, Physics, Ignition system, Hohlraum, law, General Physics and Astronomy, Plasma confinement, Magnetic confinement fusion, Plasma, Atomic physics, Radiation, Inertial confinement fusion, law.invention
Published
2011

15. Demonstration of Ignition Radiation Temperatures in Indirect-Drive Inertial Confinement Fusion Hohlraums

Author

L. V. Berzins, L. M. Kegelmeyer, D. R. Hart, L. J. Suter, M. Shor, Ronald B. Robinson, S. S. Alvarez, G. Gururangan, Robert L. Kauffman, C. T. Warren, R. Darbee, Andrew MacPhee, J. R. Nelson, D. A. Smauley, M. J. Fischer, K. S. Andersson, D. A. Callahan, L. J. Atherton, D. S. Hey, J. D. Kilkenny, T. Ma, J. H. Kamperschroer, T. Frazier, T. J. Clancy, E. A. Williams, P. A. Adams, C. Thai, Laurent Divol, G. J. Edwards, Suhas Bhandarkar, K. Work, M. D. Magat, S. Hunter, Stephen P. Vernon, T. L. Lee, Rolf K. Reed, J.M.Fisher, O. S. Jones, D. Trummer, G. N. Gawinski, G. Antonini, M. P. Johnston, A. J. Mackinnon, M. E. Sheldrick, T. R. Huppler, B. A. Wilson, J. P. Holder, P. L. Stratton, Yiping Chen, J. Jackson, S. Sailors, John Moody, Mark J. Schmitt, L. K. Smith, R. G. Hartley, E. J. Bond, P. Datte, S. Burns, B. McHale, G. Bardsley, D. T. Boyle, D. R. Bopp, E. L. Dewald, J. E. Hamblen, L. Willis, K. G. Krauter, J. R. Schaffer, D. G. Mathisen, M. D. Rosen, J. Morris, M.S.Hutton, G. T. Lau, N. W. Lum, G. Hermes, G. A. Deis, K. N. La Fortune, M. C. Johnson, J. Neumann, C. C. Widmayer, Steven H. Langer, L. F. Finnie, M. C. Witte, K. King, Michael Stadermann, E. A. Stout, M. G. Miller, Wendi Sweet, T. G. Stone, E. A. Tekle, P. M. Danforth, H. Chandrasekaran, D. Larson, M. F. Swisher, J. T. Fink, G. Frieder, L. Bezerides, Kenneth S. Jancaitis, A. L. Throop, B. L. Lechleiter, S. N. Dixit, Kevin S. White, C. Chang, M. K. Shiflett, G. A. Kyrala, F. Stanley, J. Braucht, John Kline, S. M. Gross, A. Baron, R G Beeler, S. Azevedo, R. A. London, T. E. Mills, G Brunton, Marilyn Schneider, M. J. Dailey, R. C. Montesanti, J. Dugorepec, A. J. Churby, I. L. Maslennikov, D. Latray, F. Barbosa, P. A. Arnold, A. A. Marsh, J. J. Rhodes, G. L. Tietbohl, Alexander Thomas, D. B. Dobson, J. M. Tillman, L. L. Silva, G. Erbert, D. A. Barker, R. D. Demaret, J. A. Davis, S. M. Glenn, J. Klingmann, Edward I. Moses, T. M. Pannell, R. T. Shelton, J. M. Di Nicola, N. J. Cahayag, T. Fung, R. L. Rampke, S. Le Pape, Jay D. Salmonson, G. Ross, R. E. Olson, E. Mertens, J. D. Lindl, J. G. Lown, C. M. Estes, A. T. Rivera, Mark W. Bowers, M. Runkel, F. E. Coffield, Wade H. Williams, K. G. Koka, B. A. Hammel, L. M. Burrows, A. S. Rivenes, Daniel H. Kalantar, M. A. Vitalich, M. Y. Mauvais, D. G. Cocherell, J. Grippen, P. V. Amick, B. K. Young, J. G. Soto, A. McGrew, M. J. Edwards, Tilo Döppner, M. J. Christensen, Jeremy Kroll, J. L. Vaher, C. H. Ellerbee, T. N. Malsbury, C. A. Haynam, B. Haid, J. T. Salmon, A. J. van Prooyen, A. L. Warrick, R. Costa, A. V. Hamza, T. G. Parham, C. R. Gibson, S. A. Silva, D. Pendlton, A. W. Huey, P. M. Bell, K. P. Youngblood, B. N. M. Balaoing, Joseph Ralph, R. Rinnert, B Fishler, D. L. Hardy, K. D. Pletcher, J. Liebman, R. K. Butlin, B. Johnson, T. McCarville, L. C. Clowdus, Otto Landen, V. K. Lakamsani, B. P. Golick, F. W. Chambers, D. T. Maloy, D. L. Hipple, C. B. Foxworthy, O. D. Edwards, C. J. Roberts, T. Zaleski, S. C. Burkhart, Thomas J. Johnson, N. Lao, S. R. Marshall, J. A. Baltz, D. E. Speck, R. Miramontes, J. E. Krammen, P. J. van Arsdall, M. A. Bergonia, K. M. Skulina, R. J. Strausser, K. M. Knittel, Siegfried Glenzer, G. J. Mauger, B. E. Smith, Sally Andrews, G. Heestand, P. W. Edwards, E. M. Giraldez, John R. Celeste, N. I. Spafford, R. W. Patterson, J. Watkins, J. B. Tassano, J. C. Ellefson, B. S. Raimondi, Christoph Niemann, M. M. Montoya, M. A. Jackson, T. W. Phillips, H. Gonzales, E. Ng, Mark Eckart, D. M. Lord, S. R. Hahn, L. J. Bernardez, B. D. Cline, A. Forsman, J. W. Florio, D. Pigg, Donald F. Browning, J. L. Vickers, K. M. Morriston, G. A. Keating, G. Pavel, P. C. Dupuy, A. S. Runtal, R. L. Hibbard, P. T. Springer, T. Kohut, B. L. Pepmeier, Richard Town, W. J. Fabyan, S. Huber, A. P. Ludwigsen, G. Holtmeier, D. L. Hodtwalker, M. Neto, P. H. Gschweng, J. D. Moody, K. L. Griffin, B. V. Beeman, J. D. Hollis, E T Alger, G. M. Curnow, P. S. Yang, E. Padilla, M. W. Owens, M. J. Richardson, S. R. Robison, K. Gu, F. J. Lopez, G. Markham, M. J. Shaw, F. E. Wade, R. K. Kirkwood, Pamela K. Whitman, Cliff Thomas, L. F. Alvarez, D. K. Bradley, J. F. Meeker, J. A. Borgman, M. D. Vergino, J. McBride, W. A. Reid, D. E. Petersen, J. S. Taylor, G. T. Villanueva, M. C. Valadez, D. E. Hinkel, M. A. Weingart, K. Charron, S. W. Kramer, R. R. Lyons, S. L. Edson, Klaus Widmann, Q. M. Ngo, H. Zhang, J. B. Alfonso, S. Weaver, J. D. Driscoll, R. M. Marquez, R. M. Franks, A. Nikroo, Mark R. Hermann, R. A. Sacks, Harry B. Radousky, A. B. Langdon, Paul J. Wegner, E. K. Krieger, Pierre Michel, Richard Berger, C. Chan, J. Li, Jose Milovich, J. S. Merill, C. Powell, J. S. Zielinski, L. J. Lagin, S. P. Rogers, J. D. Tappero, N. L. Orsi, S. L. Townsend, L. Auyang, F. A. Penko, V. Rekow, P. G. Zapata, Carlos E. Castro, R. W. Carey, A. D. Casey, K. S. Segraves, D. R. Jedlovec, J. R. Cox, S. Sommer, J. C. Bell, D. L. Brinkerhoff, E. O. Vergel de Dios, G. A. Bowers, R. Zacharias, J. D. Hitchcock, S. W. Lane, R. Prasad, K. A. Moreno, B. J. MacGowan, K. Wilhelmsen, Nobuhiko Izumi, S. F. Locke, R. Chapman, O. R. Rodriguez, S. A. Vonhof, E. F. Wilson, B. L. Olejniczak, G. W. Krauter, R. Lowe-Webb, Nathan Meezan, J. R. Kimbrough, Claire Bishop, D. N. Hulsey, Joseph W. Carlson, R. N. Fallejo, M. J. Gonzalez, L. R. Belk, R. J. Wallace, S. L. Kenitzer, J. Duncan, K. Piston, J. Wen, K. E. Burns, K. L. Tribbey, S. A. Gonzales, J. H. Truong, P. Di Nicola, J. B. McCloud, Y. Lee, S. Shiromizu, T. M. Schindler, B. Burr, R. Saunders, C. Marshall, A. L. Solomon, R. C. Bettenhausen, B. M. Van Wonterghem, H. K. Loey, B. Felker, P. S. Cardinale, M. D. Finney, D. P. Atkinson, Damien Hicks, J. L. Bragg, E. G. Dzenitis, J. A. Robinson, John R. Bower, B. Riordan, S. W. Haan, M. Fedorov, Z. Alherz, S. J. Cohen, A. I. Barnes, A. Y. Chakicherla, and J. L. Reynolds

Subjects
Physics, business.industry, Physics::Optics, General Physics and Astronomy, Implosion, Radiation, Laser, law.invention, Ignition system, Optics, Physics::Plasma Physics, Hohlraum, law, Laser power scaling, Atomic physics, National Ignition Facility, business, Inertial confinement fusion, Astrophysics::Galaxy Astrophysics
Abstract

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.

Published
2011

16. Achieving large uniform tensile ductility in nanocrystalline metals

Author

Jonathan Almer, Matthew J. Kramer, Matthew F. Besser, Y. M. Wang, Ryan T. Ott, and Alex V. Hamza

Subjects
Diffraction, Materials science, General Physics and Astronomy, macromolecular substances, Strain hardening exponent, Synchrotron, Nanocrystalline material, law.invention, Nanocrystal, law, Texture (crystalline), Composite material, Electron microscope, Crystal twinning
Abstract

Synchrotron x-ray diffraction and high-resolution electron microscopy revealed the origin of different strain hardening behaviors (and dissimilar tensile ductility) in nanocrystalline Ni and nanocrystalline Co. Planar defect accumulations and texture evolution were observed in Co but not in Ni, suggesting that interfacial defects are an effective passage to promote strain hardening in truly nanograins. Twinning becomes less significant in Co when grain sizes reduce to below ~15 nm. This study offers insights into achieving excellent mechanical properties in nanocrystalline materials.

Published
2010

17. Hohlraum-Driven Mid-Z(SiO2) Double-Shell Implosions on the Omega Laser Facility and Their Scaling to NIF

Author

Matthew Bono, Jose Milovich, Harry Robey, Hae-Sim Park, Peter Amendt, and A. V. Hamza

Subjects
Physics, law, Hohlraum, Shell (structure), General Physics and Astronomy, Atomic number, Atomic physics, National Ignition Facility, Laser, Omega, Scaling, law.invention
Abstract

High-convergence, hohlraum-driven implosions of double-shell capsules using mid-Z (SiO{sub 2}) inner shells have been performed on the OMEGA laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. These experiments provide an essential extension of the results of previous low-Z (CH) double-shell implosions [P. A. Amendt et al., Phys. Rev. Lett. 94, 065004 (2005)] to materials of higher density and atomic number. Analytic modeling, supported by highly resolved 2D numerical simulations, is used to account for the yield degradation due to interfacial atomic mixing. This extended experimental database from OMEGA enables a validation of the mix model, and provides a means for quantitatively assessing the prospects for high-Z double-shell implosions on the National Ignition Facility [Paisner et al., Laser Focus World 30, 75 (1994)].

Published
2009

18. Hohlraum-driven mid-Z (SiO2) double-shell implosions on the omega laser facility and their scaling to NIF

Author

H F, Robey, P A, Amendt, J L, Milovich, H-S, Park, A V, Hamza, and M J, Bono

Abstract

High-convergence, hohlraum-driven implosions of double-shell capsules using mid-Z (SiO2) inner shells have been performed on the OMEGA laser facility [T. R. Boehly, Opt. Commun. 133, 495 (1997)]. These experiments provide an essential extension of the results of previous low-Z (CH) double-shell implosions [P. A. Amendt, Phys. Rev. Lett. 94, 065004 (2005)] to materials of higher density and atomic number. Analytic modeling, supported by highly resolved 2D numerical simulations, is used to account for the yield degradation due to interfacial atomic mixing. This extended experimental database from OMEGA enables a validation of the mix model, and provides a means for quantitatively assessing the prospects for high-Z double-shell implosions on the National Ignition Facility [Paisner, Laser Focus World 30, 75 (1994)].

Published
2009

19. Diamond at 800 GPa

Author

Alex V. Hamza, Raymond F. Smith, Gilbert Collins, Dave Braun, Juergen Biener, D. K. Bradley, Jon Eggert, Shon Prisbrey, Robert E. Rudd, and Damien Hicks

Subjects
Materials science, Peak pressure, General Physics and Astronomy, Thermodynamics, Diamond, chemistry.chemical_element, engineering.material, Compression (physics), Strength of materials, Stress level, Stress (mechanics), chemistry, Phase (matter), engineering, Composite material, Carbon
Abstract

A new compression technique, which enables the study of solids into the TPa regime, is described and used to ramp (or quasi-isentropically) compress diamond to a peak pressure of 1400 GPa. Diamond stress versus density data are reported to 800 GPa and suggest that the diamond phase is stable and has significant material strength up to at least this stress level. Data presented here are the highest ramp compression pressures by more than a factor of 5 and the highest-pressure solid equation-of-state data ever reported.

Published
2009

20. Demonstration of the density dependence of x-ray flux in a laser-driven hohlraum

Author

A. B. Reighard, R. A. Reibold, S. McAlpin, Otto Landen, C. Sorce, S. G. Glendinning, J. H. Hammer, Jochen Schein, M. D. Rosen, R. L. Hibbard, R. K. Kirkwood, M. Stevenson, W. S. Hsing, P. E. Young, R. E. Turner, A. V. Hamza, B. R. Thomas, and Joe H. Satcher

Subjects
Physics, X-ray, General Physics and Astronomy, Flux, Radiation, Kinetic energy, Laser, law.invention, Physics::Fluid Dynamics, Hohlraum, law, Front velocity, Supersonic speed, Atomic physics
Abstract

Experiments have been conducted using laser-driven cylindrical hohlraums whose walls are machined from Ta2O5 foams of 100 mg/cc and 4 g/cc densities. Measurements of the radiation temperature demonstrate that the lower density walls produce higher radiation temperatures than the high density walls. This is the first experimental demonstration of the prediction that this would occur [M. D. Rosen and J. H. Hammer, Phys. Rev. E 72, 056403 (2005)10.1103/PhysRevE.72.056403]. For high density walls, the radiation front propagates subsonically, and part of the absorbed energy is wasted by the flow kinetic energy. For the lower wall density, the front velocity is supersonic and can devote almost all of the absorbed energy to heating the wall.

Published
2008

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