37 results on '"S. H. Glenzer"'
Search Results
2. Observation of a highly conductive warm dense state of water with ultrafast pump–probe free-electron-laser measurements
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Chandra Curry, J. B. Kim, Zhijiang Chen, S. Liang, Ronald Redmer, Maximilian Schörner, S. Skruszewicz, Motoaki Nakatsutsumi, Adrien Descamps, S. H. Glenzer, X. Na, C. Roedel, Mianzhen Mo, Sven Toleikis, S. Lebovitz, Martin French, Daniel P. DePonte, P. Sperling, Benjamin K. Ofori-Okai, and Jake Koralek
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Nuclear and High Energy Physics ,Electron density ,02 engineering and technology ,Electron ,Photoionization ,QC770-798 ,021001 nanoscience & nanotechnology ,01 natural sciences ,Optical conductivity ,Atomic and Molecular Physics, and Optics ,Nuclear Energy and Engineering ,13. Climate action ,Electrical resistivity and conductivity ,Excited state ,Nuclear and particle physics. Atomic energy. Radioactivity ,0103 physical sciences ,Charge carrier ,ddc:530 ,Electrical and Electronic Engineering ,Atomic physics ,010306 general physics ,0210 nano-technology ,Refractive index - Abstract
The electrical conductivity of water under extreme temperatures and densities plays a central role in modeling planetary magnetic fields. Experimental data are vital to test theories of high-energy-density water and assess the possible development and presence of extraterrestrial life. These states are also important in biology and chemistry studies when specimens in water are confined and excited using ultrafast optical or free-electron lasers (FELs). Here we utilize femtosecond optical lasers to measure the transient reflection and transmission of ultrathin water sheet samples uniformly heated by a 13.6 nm FEL approaching a highly conducting state at electron temperatures exceeding 20 000 K. The experiment probes the trajectory of water through the high-energy-density phase space and provides insights into changes in the index of refraction, charge carrier densities, and AC electrical conductivity at optical frequencies. At excitation energy densities exceeding 10 MJ/kg, the index of refraction falls to n = 0.7, and the thermally excited free-carrier density reaches n$_e$ = 5 × 10$^{27}$ m$^{−3}$, which is over an order of magnitude higher than that of the electron carriers produced by direct photoionization. Significant specular reflection is observed owing to critical electron density shielding of electromagnetic waves. The measured optical conductivity reaches 2 × 10$^4$ S/m, a value that is one to two orders of magnitude lower than those of simple metals in a liquid state. At electron temperatures below 15 000 K, the experimental results agree well with the theoretical calculations using density-functional theory/molecular-dynamics simulations. With increasing temperature, the electron density increases and the system approaches a Fermi distribution. In this regime, the conductivities agree better with predictions from the Ziman theory of liquid metals.
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- 2021
3. Developing 'inverted-corona' fusion targets as high-fluence neutron sources
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Mark A. Cappelli, W. W. Hsing, R. D. Petrasso, Nathan Meezan, Neel Kabadi, William Riedel, A. J. Mackinnon, Matthias Hohenberger, C. Shuldberg, Otto Landen, Michael Farrell, B. Heeter, L. Aghaian, R. Heredia, F. Treffert, S. H. Glenzer, and Chad Forrest
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010302 applied physics ,Fusion ,Materials science ,Laser ,01 natural sciences ,Fluence ,Omega ,010305 fluids & plasmas ,law.invention ,Deuterium ,law ,0103 physical sciences ,Neutron source ,Neutron ,Atomic physics ,National Ignition Facility ,Instrumentation - Abstract
We present experimental studies of inverted-corona targets as neutron sources at the OMEGA Laser Facility and the National Ignition Facility (NIF). Laser beams are directed onto the inner walls of a capsule via laser-entrance holes (LEHs), heating the target interior to fusion conditions. The fusion fuel is provided either as a wall liner, e.g., deuterated plastic (CD), or as a gas fill, e.g., D2 gas. Such targets are robust to low-mode drive asymmetries, allowing for single-sided laser drive. On OMEGA, 1.8-mm-diameter targets with either a 10-μm CD liner or up to 2 atm of D2-gas fill were driven with up to 18 kJ of laser energy in a 1-ns square pulse. Neutron yields of up to 1.5 × 1010 generally followed expected trends with fill pressure or laser energy, although the data imply some mix of the CH wall into the fusion fuel for either design. Comparable performance was observed with single-sided (1x LEH) or double-sided (2x LEH) drive. NIF experiments tested the platform at scaled up dimensions and energies, combining a 15-μm CD liner and a 3-atm D2-gas fill in a 4.5-mm diameter target, laser-driven with up to 330 kJ. Neutron yields up to 2.6 × 1012 were measured, exceeding the scaled yield expectation from the OMEGA data. The observed energy scaling on the NIF implies that the neutron production is gas dominated, suggesting a performance boost from using deuterium–tritium (DT) gas. We estimate that neutron yields exceeding 1014 should be readily achievable using a modest laser drive of ∼300 kJ with a DT fill.
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- 2021
4. Collisionless shock acceleration of narrow energy spread ion beams from mixed species plasmas using 1 μm lasers
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Sergei Tochitsky, Laurent Divol, Robert Fedosejevs, B. B. Pollock, Shaun Kerr, S. H. Glenzer, Andrew Longman, L. Manzoor, Arthur Pak, Frederico Fiuza, Felicie Albert, Maxence Gauthier, C. Joshi, Nuno Lemos, D.H. Froula, A. Link, Dan Haberberger, and P. K. Patel
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Physics ,Shock wave ,Nuclear and High Energy Physics ,Physics and Astronomy (miscellaneous) ,Charge (physics) ,Surfaces and Interfaces ,Plasma ,7. Clean energy ,01 natural sciences ,Spectral line ,Physics - Plasma Physics ,010305 fluids & plasmas ,Ion ,Physics::Plasma Physics ,0103 physical sciences ,Physics::Accelerator Physics ,lcsh:QC770-798 ,Production (computer science) ,Physics - Accelerator Physics ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,Atomic physics ,010306 general physics ,Beam (structure) ,Energy (signal processing) - Abstract
Collisionless shock acceleration of protons and C$^{6+}$ ions has been achieved by the interaction of a 10$^{20}$ W/cm$^2$, 1 $\mu$m laser with a near-critical density plasma. Ablation of the initially solid density target by a secondary laser allowed for systematic control of the plasma profile. This enabled the production of beams with peaked spectra with energies of 10-18 MeV/a.m.u. and energy spreads of 10-20$\%$ with up to 3x10$^9$ particles within these narrow spectral features. The narrow energy spread and similar velocity of ion species with different charge-to-mass ratio are consistent with acceleration by the moving potential of a shock wave. Particle-in-cell simulations show shock accelerated beams of protons and C$^{6+}$ ions with energy distributions consistent with the experiments. Simulations further indicate the plasma profile determines the trade-off between the beam charge and energy and that with additional target optimization narrow energy spread beams exceeding 100 MeV/a.m.u. can be produced using the same laser conditions., Comment: Accepted for publication in Physical Review Accelerators and Beams
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- 2018
5. Probing matter at Gbar pressures at the NIF
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Gilbert Collins, Roger Falcone, S. H. Glenzer, S. Rothman, O. S. Jones, Joseph Nilsen, Andrea Kritcher, D. Chapman, S. Felker, Damian Swift, Christopher J. Keane, O. L. Landen, Benjamin Bachmann, Cliff Thomas, Hyesog Lee, E. L. Dewald, Dominik Kraus, J. H. Hammer, Paul Neumayer, Tilo Döppner, James Hawreliak, and David Strozzi
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Shock wave ,Physics ,Nuclear and High Energy Physics ,Equation of state ,Radiation ,Shock (fluid dynamics) ,Hohlraum ,Thomson scattering ,Electron temperature ,Atomic physics ,National Ignition Facility ,Doppler broadening - Abstract
We describe a platform to measure the material properties, specifically the equation of state and electron temperature, at pressures of 100 Mbar to a Gbar at the National Ignition Facility (NIF). In these experiments we launch spherically convergent shock waves into solid CH, CD, or diamond samples using a hohlraum radiation drive, in an indirect drive laser geometry. X-ray radiography is applied to measure the shock speed and infer the mass density profile, enabling determination of the material pressure and Hugoniot equation of state. X-ray scattering is applied to measure the electron temperature through probing of the electron velocity distribution via Doppler broadening.
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- 2014
6. Observations of strong ion-ion correlations in dense plasmas
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Arthur Pak, S. H. Glenzer, David Turnbull, Carsten Fortmann, O. L. Landen, Tilo Döppner, Bob Nagler, T Ma, Jan Vorberger, Gianluca Gregori, S. Le Pape, J. B. Hastings, Thomas G. White, Ulf Zastrau, Roger Falcone, Luke Fletcher, D. A. Chapman, Paul Neumayer, K. Wünsch, Eric Galtier, H. J. Lee, and Dirk O. Gericke
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Physics ,Elastic scattering ,Photon ,Physics::Plasma Physics ,Waves in plasmas ,Scattering ,Plasma diagnostics ,Plasma ,Electric potential ,Atomic physics ,Condensed Matter Physics ,Ion - Abstract
Using simultaneous spectrally, angularly, and temporally resolved x-ray scattering, we measure the pronounced ion-ion correlation peak in a strongly coupled plasma. Laser-driven shock-compressed aluminum at ∼3× solid density is probed with high-energy photons at 17.9keV created by molybdenum He-α emission in a laser-driven plasma source. The measured elastic scattering feature shows a well-pronounced correlation peak at a wave vector of k=4Å-1. The magnitude of this correlation peak cannot be described by standard plasma theories employing a linear screened Coulomb potential. Advanced models, including a strong short-range repulsion due to the inner structure of the aluminum ions are however in good agreement with the scattering data. These studies have demonstrated a new highly accurate diagnostic technique to directly measure the state of compression and the ion-ion correlations. We have since applied this new method in single-shot wave-number resolved S(k) measurements to characterize the physical properties of dense plasmas. © 2014 AIP Publishing LLC.
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- 2016
7. Temperature measurement through detailed balance in x-ray Thomson scattering
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Paul Neumayer, Tilo Döppner, Susan Regan, Otto Landen, Hyesog Lee, and S. H. Glenzer
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Physics ,Nuclear and High Energy Physics ,Radiation ,Physics::Plasma Physics ,Thomson scattering ,Electron temperature ,Detailed balance ,Plasma ,Warm dense matter ,Atomic physics ,Structure factor ,Temperature measurement ,Plasmon - Abstract
The plasma conditions in isochorically heated beryllium are measured by collective x-ray Thomson scattering. The collectively scattered Cl Ly-α x-ray line at 2.96 keV shows up- and down-shifted plasmon signals. From the detailed balance relation, i.e., the ratio of the up-shifted to the down-shifted plasmon intensities, the plasma temperature can be determined independent of model assumptions. Results are shown for an experiment in which a temperature of 18 eV was measured. Using detailed balance for temperature measurement will be important to validate models that calculate the static ion–ion structure factor Sii(k).
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- 2009
8. Equilibration dynamics and conductivity of warm dense hydrogen
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Bastian Holst, R. Bredow, H. J. Lee, Michael Schulz, Rolf Mitzner, Tim Laarmann, Thomas Tschentscher, Thomas Fennel, S. Dziarzhytski, Ulf Zastrau, Michael Wöstmann, S. Roling, Sebastian Göde, Eckhart Förster, Carsten Fortmann, S. H. Glenzer, Gianluca Gregori, Helmut Zacharias, Thomas G. White, T. Bornath, Sven Toleikis, Marion Harmand, Josef Tiggesbäumker, B. Siemer, Luke Fletcher, Andreas Przystawik, Paul Neumayer, P. Sperling, Ronald Redmer, S. Skruszewicz, Tilo Döppner, C. D. Murphy, Motoaki Nakatsutsumi, Tammy Ma, Hilbert, J. Mithen, and Andreas Becker
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Materials science ,Hydrogen ,Plasma parameters ,chemistry.chemical_element ,Electrons ,Electron ,Molecular Dynamics Simulation ,Photon energy ,7. Clean energy ,01 natural sciences ,010305 fluids & plasmas ,Ion ,X-Ray Diffraction ,Ionization ,0103 physical sciences ,ddc:530 ,010306 general physics ,Lasers ,Electric Conductivity ,Temperature ,DESY ,Plasma ,chemistry ,Hydrodynamics ,Quantum Theory ,Atomic physics - Abstract
We investigate subpicosecond dynamics of warm dense hydrogen at the XUV free-electron laser facility (FLASH) at DESY (Hamburg). Ultrafast impulsive electron heating is initiated by a â‰300-fs short x-ray burst of 92-eV photon energy. A second pulse probes the sample via x-ray scattering at jitter-free variable time delay. We show that the initial molecular structure dissociates within (0.9±0.2) ps, allowing us to infer the energy transfer rate between electrons and ions. We evaluate Saha and Thomas-Fermi ionization models in radiation hydrodynamics simulations, predicting plasma parameters that are subsequently used to calculate the static structure factor. A conductivity model for partially ionized plasma is validated by two-temperature density-functional theory coupled to molecular dynamic simulations and agrees with the experimental data. Our results provide important insights and the needed experimental data on transport properties of dense plasmas. © 2014 American Physical Society.
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- 2014
9. Observations of Continuum Depression in Warm Dense Matter with X-Ray Thomson Scattering
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Tilo Döppner, Art Pak, Laurent Divol, Roger Falcone, S. H. Glenzer, Tammy Ma, Dirk O. Gericke, D. A. Chapman, B. A. Mattern, Gerald T. Seidler, Andrea Kritcher, Jan Vorberger, O. S. Jones, Gianluca Gregori, Carsten Fortmann, Howard A. Scott, Otto Landen, and Luke Fletcher
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Coalescence (physics) ,Physics ,Thomson scattering ,Scattering ,Astrophysics::High Energy Astrophysical Phenomena ,Ionization ,General Physics and Astronomy ,Plasma ,Electron ,Atomic physics ,Warm dense matter ,Spectral line - Abstract
Detailed measurements of the electron densities, temperatures, and ionization states of compressed CH shells approaching pressures of 50 Mbar are achieved with spectrally resolved x-ray scattering. Laser-produced 9 keV x-rays probe the plasma during the transient state of three-shock coalescence. High signal-to-noise x-ray scattering spectra show direct evidence of continuum depression in highly degenerate warm dense matter states with electron densities ${n}_{e}g1{0}^{24}\text{ }{\mathrm{cm}}^{\ensuremath{-}3}$. The measured densities and temperatures agree well with radiation-hydrodynamic modeling when accounting for continuum lowering in calculations that employ detailed configuration accounting.
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- 2014
10. Resolving ultrafast heating of dense cryogenic hydrogen
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J. Tiggesbäumker, J. Mithen, Motoaki Nakatsutsumi, V. Hilbert, Tammy Ma, Michael Schulz, Rolf Mitzner, R. Bredow, Thomas G. White, Helmut Zacharias, Gianluca Gregori, Eckhart Förster, Luke Fletcher, D Hochhaus, Sebastian Göde, Th. Tschentscher, Bastian Holst, S. Dziarzhytski, P. Sperling, C. D. Murphy, Sven Toleikis, Paul Neumayer, Andreas Becker, Tilo Döppner, Michael Wöstmann, S. H. Glenzer, S. Roling, S. Skruszewicz, B. Siemer, Andreas Przystawik, Ronald Redmer, Marion Harmand, T. Bornath, H. J. Lee, Tim Laarmann, Thomas Fennel, and Ulf Zastrau
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Physics ,Hydrogen ,Free-electron laser ,General Physics and Astronomy ,chemistry.chemical_element ,Plasma ,Conductivity ,7. Clean energy ,Scattering amplitude ,chemistry ,Rise time ,Ionization ,ddc:550 ,Atomic physics ,Ultrashort pulse - Abstract
We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a ≲300 fs, 92 eV free electron laser x-ray burst. The rise of the x-ray scattering amplitude from a second x-ray pulse probes the transition from dense cryogenic molecular hydrogen to a nearly uncorrelated plasmalike structure, indicating an electron-ion equilibration time of ∼0.9 ps. The rise time agrees with radiation hydrodynamics simulations based on a conductivity model for partially ionized plasma that is validated by two-temperature density-functional theory. © 2014 American Physical Society.
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- 2014
11. High-energy 4ω probe laser for laser-plasma experiments at Nova
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J. Bower, S. H. Glenzer, B. J. MacGowan, T. L. Weiland, and A. J. Mackinnon
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Physics ,Thomson scattering ,business.industry ,Plasma ,Nova (laser) ,Laser ,Light scattering ,law.invention ,Optics ,law ,Hohlraum ,Plasma diagnostics ,Atomic physics ,business ,Instrumentation ,Inertial confinement fusion - Abstract
For the characterization of inertial confinement fusion plasmas, we implemented a high-energy 4ω probe laser at the Nova laser facility. A total energy of >50 J at 4ω, a focal spot size of order 100 μm, and a pointing accuracy of 100 μm was demonstrated for target shots. This laser provides intensities of up to 3×1014 W cm−2 and therefore fulfills high-power requirements for laser-plasma interaction experiments. The 4ω probe laser is now routinely used for Thomson scattering. Successful experiments were performed in gas-filled hohlraums at electron densities of ne>2×1021 cm−3 which represents the highest density plasma so far being diagnosed with Thomson scattering.
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- 1999
12. Hot-Spot Mix in Ignition-Scale Inertial Confinement Fusion Targets
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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
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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.
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- 2013
13. Radiative shocks produced from spherical cryogenic implosions at the National Ignition Facility
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John Kline, R. Tommasini, Damien Hicks, J. D. Lindl, O. S. Jones, Gianluca Gregori, D. T. Casey, D. K. Bradley, S. Le Pape, W. W. Hsing, N. Izumi, E. L. Dewald, Otto Landen, H.-S. Park, Richard Town, Andrew MacPhee, Shahab Khan, A. J. Mackinnon, T. Ma, Harry Robey, Edward I. Moses, James Ross, S. M. Glenn, S. V. Weber, J. D. Kilkenny, R. E. Olson, Bruce Remington, V. A. Smalyuk, Debra Callahan, J. D. Moody, Maria Gatu Johnson, Melissa Edwards, R. Bennedetti, Arthur Pak, George A. Kyrala, Gary Grim, J. A. Frenje, J. Atherton, Laurent Divol, S. H. Glenzer, Tilo Döppner, Nathan Meezan, Laurent Masse, B. J. MacGowan, and J. E. Ralph
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Shock wave ,Physics ,Astrophysics::High Energy Astrophysical Phenomena ,Implosion ,Atmospheric-pressure plasma ,Mechanics ,Radius ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Physics::Plasma Physics ,13. Climate action ,Hohlraum ,0103 physical sciences ,Radiative transfer ,Atomic physics ,010306 general physics ,National Ignition Facility ,Inertial confinement fusion ,Astrophysics::Galaxy Astrophysics - Abstract
Spherically expanding radiative shock waves have been observed from inertially confined implosion experiments at the National Ignition Facility. In these experiments, a spherical fusion target, initially 2 mm in diameter, is compressed via the pressure induced from the ablation of the outer target surface. At the peak compression of the capsule, x-ray and nuclear diagnostics indicate the formation of a central core, with a radius and ion temperature of ∼20 μm and ∼ 2 keV, respectively. This central core is surrounded by a cooler compressed shell of deuterium-tritium fuel that has an outer radius of ∼40 μm and a density of >500 g/cm3. Using inputs from multiple diagnostics, the peak pressure of the compressed core has been inferred to be of order 100 Gbar for the implosions discussed here. The shock front, initially located at the interface between the high pressure compressed fuel shell and surrounding in-falling low pressure ablator plasma, begins to propagate outwards after peak compression has been reached. Approximately 200 ps after peak compression, a ring of x-ray emission created by the limb-brightening of a spherical shell of shock-heated matter is observed to appear at a radius of ∼100 μm. Hydrodynamic simulations, which model the experiment and include radiation transport, indicate that the sudden appearance of this emission occurs as the post-shock material temperature increases and upstream density decreases, over a scale length of ∼10 μm, as the shock propagates into the lower density (∼1 g/cc), hot (∼250 eV) plasma that exists at the ablation front. The expansion of the shock-heated matter is temporally and spatially resolved and indicates a shock expansion velocity of ∼300 km/s in the laboratory frame. The magnitude and temporal evolution of the luminosity produced from the shock-heated matter was measured at photon energies between 5.9 and 12.4 keV. The observed radial shock expansion, as well as the magnitude and temporal evolution of the luminosity from the shock-heated matter, is consistent with 1-D radiation hydrodynamic simulations. Analytic estimates indicate that the radiation energy flux from the shock-heated matter is of the same order as the in-flowing material energy flux, and suggests that this radiation energy flux modifies the shock front structure. Simulations support these estimates and show the formation of a radiative shock, with a precursor that raises the temperature ahead of the shock front, a sharp μ m-scale thick spike in temperature at the shock front, followed by a post-shock cooling layer. © 2013 AIP Publishing LLC.
- Published
- 2013
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14. Using collective x-ray Thomson scattering to measure temperature and density of warm dense matter
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P. F. Davis, Susan Regan, S. H. Glenzer, Andrea Kritcher, Hyesog Lee, Tilo Döppner, and Otto Landen
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Physics ,Electron density ,symbols.namesake ,Physics::Plasma Physics ,Thomson scattering ,symbols ,Electron temperature ,Electron ,Rayleigh scattering ,Atomic physics ,Warm dense matter ,Plasma oscillation ,Plasmon - Abstract
Collective x-ray Thomson scattering allows measuring plasmons, i.e electron plasma oscillations (Langmuir waves). This is manifest in the appearance of spectrally up- and down-shifted spectral features in addition to the Rayleigh signal. The ratio of the up- and down-shifted signals is directly related to detailed balance, allowing to determine the plasma temperature from first principles. The spectral shift of the plasmon signals is sensitive to temperature and electron density. We discuss the experimental considerations that have to be fulfilled to observe plasmon signals with x-ray Thomson scattering. As an example, we describe an experiment that used the Cl Ly-{alpha} x-ray line at 2.96 keV to measure collective Thomson scattering from solid beryllium, isochorically heated to 18 eV. Since temperature measurement based on detailed balance is based on first principles, this method is important to validate models that, for example, calculate the static ion-ion structure factor S{sub ii}(k).
- Published
- 2009
15. Hard x-ray spectrometer for hot electron measurements on the National Ignition Facility
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R. Tommasini, E. L. Dewald, J. Hill, H. Kather, L. J. Suter, N. Meezan, E. J. Bond, Otto Landen, D. Meeker, Cliff Thomas, Robert L. Kauffman, S. H. Glenzer, and J.M. Foster
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Nuclear physics ,Ignition system ,Physics ,Fusion ignition ,Hohlraum ,law ,Bremsstrahlung ,Plasma diagnostics ,Electron ,Atomic physics ,National Ignition Facility ,Inertial confinement fusion ,law.invention - Abstract
The upcoming National Ignition Campaign (NIC) on the National Ignition Facility (NIF) will attempt to achieve fusion ignition and gain using a ≈1 MJ laser-driven hohlraum. In order to maintain the fuel on a low enough adiabat so it reaches adequate compressed areal density, the amount of ≫ 170 keV hot electrons generated, those that can penetrate to the DT fuel [1] has to be below 0.25 J for the first 7 ns of the drive pulse, and stay below 500 J during the peak of the pulse at 13 ns. On the NIF, hot electron spectra and yields are inferred from the ≪ 20 keV bremsstrahlung spectrum generated by the hot electrons depositing energy in the hohlraum walls using an absolutely calibrated Filter-Fluorescer (FFLEX) diagnostic [2]. An early version of FFLEX successfully characterized 20 – 120 keV brems-strahlung spectra generated by electrons having 30 keV temperature on vacuum hohlraum experiments using 4 NIF beams [3]. For the upcoming NIC experiments, however, the FFLEX must be capable of measuring x-ray spectra above 170 keV characteristic of electrons above that energy. We propose high energy (100 – 300 keV) channel upgrades that will allow us to estimate the generated hot electron populations with the required accuracy.
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- 2009
16. Magnetically Controlled Optical Plasma Waveguide for Electron Acceleration
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B. B. Pollock, P. Davis, L. Divol, S. H. Glenzer, J. P. Palastro, D. Price, G. R. Tynan, D. H. Froula, Carl B. Schroeder, Wim Leemans, and Eric Esarey
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Physics ,Heat flux ,law ,Physics::Accelerator Physics ,Particle accelerator ,Atmospheric-pressure plasma ,Plasma ,Electron ,Atomic physics ,Plasma acceleration ,Laser ,Magnetic field ,law.invention - Abstract
In order to produce multi‐Gev electrons from Laser Wakefield Accelerators, we present a technique to guide high power laser beams through underdense plasma. Experimental results from the Jupiter Laser Facility at the Lawrence Livermore National Laboratory that show density channels with minimum plasma densities below 5×1017 cm−3 are presented. These results are obtained using an external magnetic field (
- Published
- 2009
17. Study of x-ray radiation from a laser wakefield accelerator
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V. Leurent, P. Michel, C. E. Clayton, L. Divol, T. Döppner, S. H. Glenzer, C. Joshi, K. A. Marsh, A. Pak, J. P. Palastro, B. B. Pollock, J. Ralph, G. Tynan, T. L. Wang, D. H. Froula, Carl B. Schroeder, Wim Leemans, and Eric Esarey
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Physics ,Spectrometer ,law ,Cathode ray ,Physics::Accelerator Physics ,Particle accelerator ,Electron ,Atomic physics ,Betatron ,Laser ,Plasma acceleration ,Synchrotron ,law.invention - Abstract
A Laser Wakefield Accelerator (LWFA) is under development at Lawrence Livermore National Laboratory (LLNL) to produce electron bunches with GeV class energy and energy spreads of a few‐percent. The interaction of a high power (200 TW), short pulse (50 fs) laser with neutral He gas can generate quasi‐monoenergetic electron beams at energies up to 1 GeV [1]. The laser pulse can be self‐guided over 1 cm overcoming the limitation of vacuum diffraction. X‐ray betatron radiation is emitted while the accelerated electrons undergo oscillations in the wakefield electrostatic field. Here we present electron spectra measurements with a two screen spectrometer allowing to measure both the electron energy and the transverse deflection at the plasma exit. We have measured monoenergetic electron beams above 300 MeV. Furthermore a forward directed x‐ray beam is observed. Preliminary measurements of the spectrum are in reasonable agreement with the calculated betatron spectrum in the synchrotron asymptotic limit using the measured electron beam parameters.
- Published
- 2009
18. Turning solid aluminium transparent by intense soft X-ray photoionization
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Dorota Klinger, P.A. Heimann, Ryszard Sobierajski, Gianluca Gregori, R. Thiele, R. Schott, Marta Fajardo, S. Duesterer, Karel Saksl, Libor Juha, Carsten Fortmann, Justin Wark, David Riley, Tilo Döppner, Karl-Heinz Meiwes-Broer, T. Whitcher, R. R. Fäustlin, Sven Toleikis, Jacek Krzywinski, J. Tiggesbäumker, Jaromir Chalupsky, P. Mercere, Saša Bajt, Tim Laarmann, Andreas Przystawik, Fida Khattak, Ulf Zastrau, J. Cihelka, Marek Jurek, Hyesog Lee, S. H. Glenzer, Bob Nagler, S. M. Vinko, Eckhart Förster, Sebastian Göde, Thomas Tschentscher, H.J. Vollmer, William J. Murphy, Thomas Dzelzainis, Heidi Reinholz, Richard W. Lee, Tomáš Burian, Elsa Abreu, Michaela Kozlova, Gerd Röpke, Eric Galtier, Art J. Nelson, Ronald Redmer, Ingo Uschmann, A.R. Khorsand, Frank B. Rosmej, Henry N. Chapman, T. Bornath, and Věra Hájková
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Physics ,Optical physics ,General Physics and Astronomy ,chemistry.chemical_element ,Saturable absorption ,Photoionization ,Plasma ,Physicist ,Warm dense matter ,chemistry ,Aluminium ,Physics::Space Physics ,ddc:530 ,Atomic physics ,Inertial confinement fusion - Abstract
Saturable absorption is a phenomenon readily seen in the optical and infrared wavelengths. It has never been observed in core-electron transitions owing to the short lifetime of the excited states involved and the high intensities of the soft X-rays needed. We report saturable absorption of an L-shell transition in aluminium using record intensities over 10 16 W cm 2 at a photon energy of 92 eV. From a consideration of the relevant timescales, we infer that immediately after the X-rays have passed, the sample is in an exotic state where all of the aluminium atoms have an L-shell hole, and the valence band has approximately a 9 eV temperature, whereas the atoms are still on their crystallographic positions. Subsequently, Auger decay heats the material to the warm dense matter regime, at around 25 eV temperatures. The method is an ideal candidate to study homogeneous warm dense matter, highly relevant to planetary science, astrophysics and inertial confinement fusion. © 2009 Macmillan Publishers Limited. All rights reserved.
- Published
- 2009
19. Demonstration of x-ray Thomson scattering using picosecond K-alpha x-ray sources in the characterization of dense heated matter
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A. L. Kritcher, S. H. Glenzer, H. J. Lee, Roger Falcone, Paul Neumayer, Tilo Döppner, and Edward C. Morse
- Subjects
Physics ,X-ray Raman scattering ,Physics::Plasma Physics ,Scattering ,Thomson scattering ,Atomic physics ,Inelastic scattering ,Warm dense matter ,National Ignition Facility ,Instrumentation ,Inertial confinement fusion ,Small-angle neutron scattering - Abstract
We present K-alpha x-ray Thomson scattering from shock compressed matter for use as a diagnostic in determining the temperature, density, and ionization state with picosecond resolution. The development of this source as a diagnostic as well as stringent requirements for successful K-alpha x-ray Thomson scattering are addressed. Here, the first elastic and inelastic scattering measurements on a medium size laser facility have been observed. We present scattering data from solid density carbon plasmas with1x10(5) photons in the elastic peak that validate the capability of single shot characterization of warm dense matter and the ability to use this scattering source at future free electron lasers and for fusion experiments at the National Ignition Facility (NIF), LLNL.
- Published
- 2008
20. Thomson Scattering at FLASH - Status Report
- Author
-
Gianluca Gregori, S Toleikis, K H Meiwes-Broer, Tilo Döppner, E Forster, T. Bornath, R Thiele, H. J. Lee, P. Radcliffe, L. Cao, G Ropke, S. Dusterer, Ingo Uschmann, N X Truong, S. H. Glenzer, Carsten Fortmann, Sebastian Göde, T Tschentscher, R. Irsig, Ronald Redmer, Andreas Przystawik, J. Tiggesbäumker, R. R. Fäustlin, A Holl, H Reinholz, Tim Laarmann, and Ulf Zastrau
- Subjects
Physics ,Electron density ,law ,Thomson scattering ,Free-electron laser ,Electron temperature ,Plasma ,Atomic physics ,Warm dense matter ,Laser ,Inertial confinement fusion ,law.invention - Abstract
The basic idea is to implement Thomson scattering with free electron laser (FEL) radiation at near-solid density plasmas as a diagnostic method which allows the determination of plasma temperatures and densities in the warm dense matter (WDM) regime (free electron density of n{sub e} = 10{sup 21}-10{sup 26} cm{sup -3} with temperatures of several eV). The WDM regime [1] at near-solid density (n{sub e} = 10{sup 21}-10{sup 22} cm{sup -3}) is of special interest because, it is where the transition from an ideal plasma to a degenerate, strongly coupled plasma occurs. A systematic understanding of this largely unknown WDM domain is crucial for the modeling and understanding of contemporary plasma experiments, like laser shock-wave or Z-pinch experiments as well as for inertial confinement fusion (ICF) experiments as the plasma evolution follows its path through this domain.
- Published
- 2007
21. Thomson Scattering Measurements of Plasma Dynamics
- Author
-
T Tschentscher, S Toleikis, A. Höll, E Forster, P Neumayer, S. H. Glenzer, L F Cao, and R Redmer
- Subjects
Physics ,Physics::Plasma Physics ,Scattering ,Thomson scattering ,Thermodynamic equilibrium ,Electron temperature ,Order (ring theory) ,Electron ,Plasma ,Warm dense matter ,Atomic physics - Abstract
The authors propose to investigate the dynamics of plasmas in the warm dense matter (WDM) regime on ultra-short time scales. Accessible plasma conditions are in the density range of n = 10{sup 20} - 10{sup 23} cm{sup -3} and at moderate temperatures of T = 1 - 20 eV. These plasmas are of importance for laboratory astrophysics, high energy density science and inertial confinement fusion. They are characterized by a coupling parameter of {Lambda} {approx}> 1, where electromagnetic interactions are of the same order as the kinetic energy. The high density of the plasma makes it opaque to radiation in the visible range and, as a consequence, UV up to x-ray radiation can be used to probe such systems. Therefore a wide range in the temperature-density plane of WDM is presently unexplored and only the VUV-FEL opens for the first time the opportunity for its detailed investigation. In equilibrium, the macroscopic state of the plasma is completely characterized by its density and temperature. In pump-probe experiments however, the plasma is initially in a nonequilibrium state and relaxes towards equilibrium within the relaxation time {tau}{sub R}. For t > {tau}{sub R}, the plasma is in an equilibrium state and expands hydrodynamicallymore » on a time scale {tau}{sub H}. The proposed experiment measures the time-resolved Thomson scattering signal with the VUV-FEL radiation characterizing the plasma in equilibrium and nonequilibrium states. Both regimes are extremely interesting and will provide new insight into the following phenomena: (1) details of nonequilibrium correlations, (2) relaxation phenomena, (3) hydrodynamic expansion, (4) recombination kinetics. The time-resolved Thomson scattering signal is obtained in a pump-probe experiment by varying the delay between pump and probe. The final stage of the relaxation process (t {approx} {tau}{sub R}) is of special interest since the plasma components (electrons and ion species) can be assumed to be in quasi-equilibrium. This allows for accurate measurements of the electron temperature using the detailed balance relation. For times t {approx} {tau}{sub H}) the hydrodynamic expansion of the plasma sets in. Detailed information on the evolution of the plasma in this regime is available from sophisticated hydrodynamic computer simulations which can be tested with the proposed measurements. With the decreasing plasma density due to the expansion, recombination processes become important and need to be considered as well.« less
- Published
- 2006
22. Temperature Measurements of Dense Plasmas by Detailed Balance
- Author
-
R Redmer, A Holl, Carsten Fortmann, T Tschentscher, S. H. Glenzer, R Thiele, E Forster, G Ropke, S Toleikis, L Cao, and H Reinholz
- Subjects
Physics ,Physics::Plasma Physics ,Thomson scattering ,Scattering ,Electron temperature ,Electron ,Plasma ,Atomic physics ,Inelastic scattering ,Warm dense matter ,Inertial confinement fusion - Abstract
Plasmas at high electron densities of n{sub e} = 10{sup 20} - 10{sup 26} cm{sup -3} and moderate temperatures T{sub e} = 1 - 20 eV are important for laboratory astrophysics, high energy density science and inertial confinement fusion. These plasmas are usually referred to as Warm Dense Matter (WDM) and are characterized by a coupling parameter of {Lambda} {approx}> 1 where correlations become important. The characterization of such plasmas is still a challenging task due to the lack of direct measurement techniques for temperatures and densities. They propose to measure the Thomson scattering spectrum of vacuum-UV radiation off density fluctuations in the plasma. Collective Thomson scattering provides accurate data for the electron temperature applying first principles. Further, this method takes advantage of the spectral asymmetry resulting from detailed balance and is independent of collisional effects in these dense systems.
- Published
- 2006
23. X-ray continuum emission spectroscopy from hot dense matter at Gbar pressures
- Author
-
Dominik Kraus, S. H. Glenzer, A. L. Kritcher, D. A. Chapman, Tammy Ma, James Hawreliak, B. Bachmann, S. Le Pape, Otto Landen, Gilbert Collins, Roger Falcone, Paul Neumayer, Tilo Döppner, and D. C. Swift
- Subjects
Shock wave ,Physics ,X-ray spectroscopy ,Photon ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Photon energy ,Electron temperature ,Plasma diagnostics ,Emission spectrum ,Atomic physics ,National Ignition Facility ,Instrumentation ,Astrophysics::Galaxy Astrophysics - Abstract
We have measured the time-resolved x-ray continuum emission spectrum of ∼30 times compressed polystyrene created at stagnation of spherically convergent shock waves within the Gbar fundamental science campaign at the National Ignition Facility. From an exponential emission slope between 7.7 keV and 8.1 keV photon energy and using an emission model which accounts for reabsorption, we infer an average electron temperature of 375 ± 21 eV, which is in good agreement with HYDRA-1D simulations.
- Published
- 2014
24. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (invited)
- Author
-
Gianluca Gregori, Philip Heimann, Tammy Ma, Sebastien LePape, David Turnbull, Tilo Döppner, Thomas G. White, B. Barbrel, H. J. Lee, S. H. Glenzer, Roger Falcone, J. B. Hastings, Mingsheng Wei, Bob Nagler, Eric Galtier, Ulf Zastrau, Maxence Gauthier, Luke Fletcher, and Arthur Pak
- Subjects
Physics ,business.industry ,Thomson scattering ,Astrophysics::High Energy Astrophysical Phenomena ,Physics::Optics ,Warm dense matter ,Velocity interferometer system for any reflector ,Linear particle accelerator ,Shock (mechanics) ,Optical pumping ,Optics ,Physics::Accelerator Physics ,Plasma diagnostics ,Atomic physics ,business ,Instrumentation ,Plasmon - Abstract
Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.
- Published
- 2014
25. Intensity Limits for Propagation of0.527 μmLaser Beams through Large-Scale-Length Plasmas for Inertial Confinement Fusion
- Author
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J. D. Moody, W. Seka, R. K. Kirkwood, C. Sorce, Nathan Meezan, A. J. Mackinnon, R. E. Bahr, Laurent Divol, D.H. Froula, L. J. Suter, S. H. Glenzer, C. Niemann, O. S. Jones, and Gianluca Gregori
- Subjects
Physics ,Scale (ratio) ,business.industry ,Scattering ,General Physics and Astronomy ,Plasma ,Laser ,law.invention ,Intensity (physics) ,Ignition system ,Optics ,Physics::Plasma Physics ,law ,Atomic physics ,business ,Inertial confinement fusion ,Beam (structure) - Abstract
We have established the intensity limits for propagation of a frequency-doubled (2omega, 527 nm) high intensity interaction beam through an underdense large-scale-length plasma. We observe good beam transmission at laser intensities at or below 2x10(14) W/cm(2) and a strong reduction at intensities up to 10(15) W/cm(2) due to the onset of parametric scattering instabilities. We show that temporal beam smoothing by spectral dispersion allows a factor of 2 higher intensities while keeping the beam spray constant, which establishes frequency-doubled light as an option for ignition and burn in inertial confinement fusion experiments.
- Published
- 2005
26. Multi-keV x-ray conversion from prepulsed foil experiments
- Author
-
Michel Naudy, Daniele Babonneau, Robert L. Kauffman, Kevin B. Fournier, John F. Davis, Bruno Villette, Sylvie Depierreux, Jacob Grun, S. H. Glenzer, J.-P. Jadaud, Christina Back, L. J. Suter, F. Girard, M. Primout, and M. C. Miller
- Subjects
Materials science ,Photon ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Energy conversion efficiency ,X-ray ,chemistry.chemical_element ,Plasma ,Laser ,Copper ,law.invention ,Optics ,chemistry ,law ,Atomic physics ,business ,FOIL method ,Titanium - Abstract
Starting from FCI2 simulations showing good multi-keV conversion efficiencies of a preformed plasm from thin foils heated by two laser pulses, experiments have been performed with titanium and copper on the Omega laser facility at University of Rochester. The advantages of using this method are efficiencies close to gas targets due to the under-dense plasma created by the pre-pulse and X-ray emissions available at high photon energies that cannot be reached with gas targets. Optimum parameters (laser intensities, delay between the two pulses and thickness of the foil) for titanium and copper foils were estimated from simulations. An increase in the multi-keV conversion efficiency (above 4 keV) by a factor of 2, compared to the case without pre-pulse, is clearly shown on titanium targets. X-ray emission was measured by different diagnostics in good agreement and close to simulations results.
- Published
- 2004
27. X-ray scattering from solid density plasmas
- Author
-
Gianluca Gregori, S. W. Pollaine, O. L. Landen, Dustin Froula, S. H. Glenzer, Forrest J. Rogers, and R. S. Wallace
- Subjects
Physics ,Elastic scattering ,Quasielastic scattering ,X-ray Raman scattering ,Scattering ,Astrophysics::High Energy Astrophysical Phenomena ,Scattering theory ,Biological small-angle scattering ,Mott scattering ,Atomic physics ,Inelastic scattering ,Condensed Matter Physics - Abstract
Measurements of the microscopic properties of dense matter have been demonstrated by applying spectrally resolved multi-keV x-ray scattering. The scattering spectra from solid density beryllium show the inelastic Compton-down shifted feature that is spectrally broadened when heating the solid density plasmas isochorically and homogeneously to temperatures of several times the Fermi energy. The spectral shape of the inelastic scattering component provides an accurate measurement of the temperature, and the intensity ratio of inelastic to elastic scattering measures the ionization balance. These measurements extend the powerful technique of Thomson scattering [S. H. Glenzer et al., Phys. Plasmas 7, 2149 (1999)] to the x-ray regime for independent measurements of the plasma parameters of solid density and super dense laboratory plasmas. This new technique has wide applications to investigate the previously inaccessible regimes of dense matter, from Fermi degenerate, to strongly coupled, to high temperature i...
- Published
- 2003
28. Investigation of the Electronic Structure of Solid Density Plasmas by X-Ray Scattering
- Author
-
G Gregori, S H Glenzer, F J Forest, S Kuhlbrodt, R Redmer, G Faussurier, C Blancard, P Renaudin, and O L Landen
- Subjects
Physics ,Electron density ,Physics::Plasma Physics ,Scattering ,Dynamic structure factor ,Physics::Space Physics ,Electron temperature ,Electronic structure ,Plasma ,Electron ,Atomic physics ,Inertial confinement fusion - Abstract
We present an improved analytical expression for the x-ray dynamic structure factor from a dense plasma which includes the effects of weakly bound electrons. This result can be applied to describe scattering from low to moderate Z plasmas, and it covers the entire range of plasma conditions that can be found in inertial confinement fusion experiments, from ideal to degenerate up to moderately coupled systems. We use our theory to interpret x-ray scattering experiments from solid density carbon plasma and to extract accurate measurements of electron temperature, electron density and charge state. We use our experimental results to validate various equation-of-state models for carbon plasmas.
- Published
- 2003
29. Hohlraum energetics scaling to 520 TW on the National Ignition Facility
- Author
-
J. L. Kline, D. A. Callahan, S. H. Glenzer, N. B. Meezan, J. D. Moody, D. E. Hinkel, O. S. Jones, A. J. MacKinnon, R. Bennedetti, R. L. Berger, D. Bradley, E. L. Dewald, I. Bass, C. Bennett, M. Bowers, G. Brunton, J. Bude, S. Burkhart, A. Condor, J. M. Di Nicola, P. Di Nicola, S. N. Dixit, T. Doeppner, E. G. Dzenitis, G. Erbert, J. Folta, G. Grim, S. Glenn, A. Hamza, S. W. Haan, J. Heebner, M. Henesian, M. Hermann, D. G. Hicks, W. W. Hsing, N. Izumi, K. Jancaitis, D. Kalantar, S. F. Khan, R. Kirkwood, G. A. Kyrala, K. LaFortune, O. L. Landen, L. Lagin, D. Larson, S. Le Pape, T. Ma, A. G. MacPhee, P. A. Michel, P. Miller, M. Montincelli, A. S. Moore, A. Nikroo, M. Nostrand, R. E. Olson, A. Pak, H. S. Park, J. P. Patel, L. Pelz, J. Ralph, S. P. Regan, H. F. Robey, M. D. Rosen, J. S. Ross, M. B. Schneider, M. Shaw, V. A. Smalyuk, D. J. Strozzi, T. Suratwala, L. J. Suter, R. Tommasini, R. P. J. Town, B. Van Wonterghem, P. Wegner, K. Widmann, C. Widmayer, H. Wilkens, E. A. Williams, M. J. Edwards, B. A. Remington, B. J. MacGowan, J. D. Kilkenny, J. D. Lindl, L. J. Atherton, S. H. Batha, and E. Moses
- Subjects
Physics ,Ignition system ,Hohlraum ,law ,Implosion ,Plasma diagnostics ,Radiation ,Atomic physics ,Condensed Matter Physics ,National Ignition Facility ,Laser ,Inertial confinement fusion ,law.invention - Abstract
Indirect drive experiments have now been carried out with laser powers and energies up to 520 TW and 1.9 MJ. These experiments show that the energy coupling to the target is nearly constant at 84% ± 3% over a wide range of laser parameters from 350 to 520 TW and 1.2 to 1.9 MJ. Experiments at 520 TW with depleted uranium hohlraums achieve radiation temperatures of ∼330 ± 4 eV, enough to drive capsules 20 μm thicker than the ignition point design to velocities near the ignition goal of 370 km/s. A series of three symcap implosion experiments with nearly identical target, laser, and diagnostics configurations show the symmetry and drive are reproducible at the level of ±8.5% absolute and ±2% relative, respectively.
- Published
- 2013
30. Simultaneous imaging electron- and ion-feature Thomson scattering measurements of radiatively heated Xe
- Author
-
S. H. Glenzer, B. B. Pollock, S. Kuschel, James Ross, J Meinecke, Laurent Divol, C. Stoafer, Jessica Shaw, and George Tynan
- Subjects
Electron density ,Materials science ,Thomson scattering ,Scattering ,Temporal resolution ,Electron temperature ,Plasma diagnostics ,Electron ,Atomic physics ,Instrumentation ,Ion - Abstract
Uniform density and temperature Xe plasmas have been produced over4 mm scale-lengths using x-rays generated in a cylindrical Pb cavity. The cavity is 750 μm in depth and diameter, and is heated by a 300 J, 2 ns square, 1054 nm laser pulse focused to a spot size of 200 μm at the cavity entrance. The plasma is characterized by simultaneous imaging Thomson scattering measurements from both the electron and ion scattering features. The electron feature measurement determines the spatial electron density and temperature profile, and using these parameters as constraints in the ion feature analysis allows an accurate determination of the charge state of the Xe ions. The Thomson scattering probe beam is 40 J, 200 ps, and 527 nm, and is focused to a 100 μm spot size at the entrance of the Pb cavity. Each system has a spatial resolution of 25 μm, a temporal resolution of 200 ps (as determined by the probe duration), and a spectral resolution of 2 nm for the electron feature system and 0.025 nm for the ion feature system. The experiment is performed in a Xe filled target chamber at a neutral pressure of 3-10 Torr, and the x-rays produced in the Pb ionize and heat the Xe to a charge state of 20±4 at up to 200 eV electron temperatures.
- Published
- 2012
31. Charged-particle spectroscopy for diagnosing shock ρR and strength in NIF implosions
- Author
-
N. Sinenian, Tilo Döppner, J. D. Kilkenny, S. V. Weber, C. K. Li, Rachna Prasad, Christian Stoeckl, Gilbert Collins, Scott Sepke, R. E. Olson, E. L. Dewald, Mary Sue Richardson, Otto Landen, M. McKernan, Edward I. Moses, Michael Rosenberg, V. Y. Glebov, Damien Hicks, F. H. Séguin, S. H. Glenzer, D. Wilson, R. D. Petrasso, R. J. Leeper, R. A. London, D. T. Casey, John Kline, George A. Kyrala, Alex Zylstra, M. Gatu Johnson, A. J. Mackinnon, Hong Sio, J. A. Frenje, T. C. Sangster, H. G. Rinderknecht, K. M. Knittel, R. M. Bionta, Stephan Friedrich, Melissa Edwards, A. Nikroo, J. R. Rygg, Mario Manuel, Debra Callahan, C. Waugh, R. Zacharias, J. E. Ralph, and N. Meezan
- Subjects
Physics ,Range (particle radiation) ,Proton ,Spectrometer ,Nuclear Theory ,Stopping power ,Charged particle ,law.invention ,Nuclear physics ,Ignition system ,Physics::Plasma Physics ,law ,Physics::Accelerator Physics ,Atomic physics ,Nuclear Experiment ,Spectroscopy ,National Ignition Facility ,Instrumentation - Abstract
The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign diagnostic. The WRF measures the spectrum of protons from D-(3)He reactions in tuning-campaign implosions containing D and (3)He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total ρR through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.
- Published
- 2012
32. 4ω Thomson scattering probe for high-density plasma characterization at Titan
- Author
-
S. H. Glenzer, M. Henesian, Steven T. Yang, B. B. Pollock, Dwight Price, John Kline, T. Weiland, and James Ross
- Subjects
Materials science ,Thomson scattering ,Plasma ,Laser ,law.invention ,Ion ,symbols.namesake ,law ,symbols ,Electron temperature ,Plasma diagnostics ,Focal Spot Size ,Atomic physics ,Titan (rocket family) ,Instrumentation - Abstract
In preparation for the upcoming experiments on the Titan laser at the Jupiter Laser Facility, a new Thomson scattering system has been designed and implemented. This system allows electron temperature and density measurements in a high-density regime (n(e)10(21) cm(-3)). A 263 nm probe has been demonstrated to produce a total energy of 15 J at 4ω(263 nm) in a 1 ns square pulse with a focal spot size of 100 μm. This probe has been used for imaging Thomson scattering of the ion feature. The goal of this study is to investigate the heating of a preformed plasma by a short-pulse heater beam.
- Published
- 2010
33. Laser wakefield acceleration at reduced density in the self-guided regime
- Author
-
B. B. Pollock, Arthur Pak, Samuel Martins, Felicie Albert, L. O. Silva, John Palastro, J. E. Ralph, K. A. Marsh, S. H. Glenzer, Jessica Shaw, Wei Lu, C. E. Clayton, Warren Mori, D.H. Froula, A. Till, and C. Joshi
- Subjects
Physics ,Jet (fluid) ,Electron density ,chemistry.chemical_element ,Electron ,Plasma ,Condensed Matter Physics ,Laser ,Linear particle accelerator ,law.invention ,chemistry ,law ,Ionization ,Physics::Atomic Physics ,Atomic physics ,Helium - Abstract
Experiments conducted using a 200 TW 60 fs laser have demonstrated up to 720 MeV electrons in the self-guided laser wakefield regime using pure helium gas jet targets. The self-trapped charge in a helium plasma was shown to fall off with decreasing electron density with a threshold at 2.5×1018 cm−3, below which no charge is measured above 100 MeV. Self-guiding, however, is shown to continue below this density limitation over distances of 14 mm with an exit spot size of 25 μm. Simulations show that injection of electrons at these densities can be assisted through ionization induced trapping in a mix of helium with 3% oxygen.
- Published
- 2010
34. Ultrafast Kα x-ray Thomson scattering from shock compressed lithium hydride
- Author
-
H. J. Lee, Dwight Price, Roger Falcone, Andrew Ng, Otto Landen, Edward C. Morse, S. H. Glenzer, A. L. Kritcher, Tilo Döppner, Bastian Holst, John I. Castor, S. M. Pollaine, Richard W. Lee, Paul Neumayer, and Ronald Redmer
- Subjects
Shock wave ,Physics ,Elastic scattering ,Electron density ,Thomson scattering ,Scattering ,Astrophysics::High Energy Astrophysical Phenomena ,Electron ,Atomic physics ,Condensed Matter Physics ,Plasma oscillation ,Plasmon - Abstract
Spectrally and temporally resolved x-ray Thomson scattering using ultrafast Ti Kα x rays has provided experimental validation for modeling of the compression and heating of shocked matter. The coalescence of two shocks launched into a solid density LiH target by a shaped 6 ns heater beam was observed from rapid heating to temperatures of 2.2 eV, enabling tests of shock timing models. Here, the temperature evolution of the target at various times during shock progression was characterized from the intensity of the elastic scattering component. The observation of scattering from plasmons, electron plasma oscillations, at shock coalescence indicates a transition to a dense metallic plasma state in LiH. From the frequency shift of the measured plasmon feature the electron density was directly determined with high accuracy, providing a material compression of a factor of 3 times solid density. The quality of data achieved in these experiments demonstrates the capability for single shot dynamic characterization...
- Published
- 2009
35. High Kα x-ray conversion efficiency from extended source gas jet targets irradiated by ultra short laser pulses
- Author
-
Andrew Collette, Carmen Constantin, H.-K. Chung, P. Neumayer, Christoph Niemann, E L Dewald, Dustin Froula, S. H. Glenzer, Andreas Kemp, Nathan Kugland, J. S. Ross, and A. L. Kritcher
- Subjects
Physics ,Jet (fluid) ,Argon ,Physics and Astronomy (miscellaneous) ,Scattering ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Energy conversion efficiency ,chemistry.chemical_element ,Plasma ,Laser ,law.invention ,Optics ,chemistry ,law ,Ionization ,Atomic physics ,business ,Astrophysics::Galaxy Astrophysics ,Ultrashort pulse laser - Abstract
The absolute laser conversion efficiency to Kα-like inner shell x-rays (integrated from Kα to Kβ) is observed to be an order of magnitude higher in argon gas jets than in solid targets due to enhanced emission from higher ionization stages following ultrashort pulse laser irradiation. Particle-in-cell and spectral simulations indicate that these observations are consistent with Kα emission from a warm Ar plasma subject to hot electron inner-shell ionization. These results demonstrate that gas jet targets are bright, high conversion efficiency, high repetition rate, debris-free multi-keV x-ray sources for spectrally resolved scattering and backlighting of rapidly evolving dense matter.
- Published
- 2008
36. Three-dimensional modeling of laser-plasma interaction: Benchmarking our predictive modeling tools versus experiments
- Author
-
R. A. London, James Ross, S. H. Glenzer, Laurent Divol, Nathan Meezan, S. N. Dixit, Bert Still, D.H. Froula, Pierre Michel, Richard Berger, David Strozzi, L. J. Suter, and E. A. Williams
- Subjects
Physics ,Thomson scattering ,Plasma ,Electron ,Condensed Matter Physics ,Laser ,Computational physics ,law.invention ,symbols.namesake ,Physics::Plasma Physics ,Hohlraum ,law ,symbols ,Electron temperature ,Atomic physics ,Rayleigh scattering ,Beam (structure) - Abstract
New experimental capabilities [Froula et al., Phys. Rev. Lett. 98, 085001 (2007)] have been developed to study laser-plasma interaction (LPI) in ignition-relevant condition at the Omega laser facility (LLE/Rochester). By shooting an interaction beam along the axis of a gas-filled hohlraum heated by up to 17kJ of heater beam energy, a millimeter-scale underdense uniform plasma at electron temperatures above 3keV was created. Extensive Thomson scattering measurements allowed to benchmark hydrodynamic simulations performed with HYDRA [Meezan et al., Phys. Plasmas 14, 056304 (2007)]. As a result of this effort, these simulations can be used with much confidence as input parameters for the LPI simulation code PF3D [Berger et al., Phys. Plasmas 5, 4337 (1998)]. In this paper, it is shown that by using accurate hydrodynamic profiles and full three-dimensional simulations including a realistic modeling of the laser intensity pattern generated by various smoothing options, whole beam three-dimensional linear kinet...
- Published
- 2008
37. Energetics of multiple-ion species hohlraum plasmas
- Author
-
Debra Callahan, Nathan Meezan, R. A. London, S. H. Glenzer, Pierre Michel, Richard Berger, D.H. Froula, Paul Neumayer, James Ross, C. Sorce, L. J. Suter, Klaus Widmann, B. J. MacGowan, and Laurent Divol
- Subjects
Physics ,Wavelength ,Electron density ,Physics::Plasma Physics ,Brillouin scattering ,Hohlraum ,Electron temperature ,Landau damping ,Atomic physics ,Condensed Matter Physics ,Inertial confinement fusion ,Ion - Abstract
A study of the laser-plasma interaction processes has been performed in multiple-ion species hohlraum plasmas at conditions similar to those expected in indirect drive inertial confinement fusion targets. Gas-filled hohlraums with electron densities of 5.5×1020 and 9×1020cm−3 are heated by 14.3kJ of laser energy (wavelength 351nm) to electron temperatures of 3keV and backscattered laser light is measured. Landau damping of the ion acoustic waves is increased by adding hydrogen to a CO2 or CF4 gas. Stimulated Brillouin backscattering of a 351nm probe beam is found to decrease monotonically with increasing Landau damping, accompanied by a comparable increase in the transmission. More efficient energy coupling into the hohlraum by suppression of backscatter from the heater beams results in an increased hohlraum radiation temperature, showing that multiple-ion species plasmas improve the overall hohlraum energetics. The reduction in backscatter is reproduced by linear gain calculations as well as detailed ful...
- Published
- 2008
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