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Development of spatially and temporally resolved electron density measurements for the assessment of radiation hydrodynamics simulations of laboratory X-ray photoionized plasmas High Energy Density Phys. (IF 1.6) Pub Date : 2024-02-28 G.S. Jaar, K.J. Swanson, R.C. Mancini, A.L. Astanovitskiy, D.C. Mayes
The photoionized plasma gas cell experiment is an established platform we use to make at-parameter () measurements of plasma properties with application to high-energy astrophysical systems. We model the experiments with 1D radiation hydrodynamics simulations using the HELIOS-CR code to inform our understanding and assist in the interpretation of results. The simulations predict that the bulk of the
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Ball lightning as a source of neutrino and muons at its entry into a dense medium High Energy Density Phys. (IF 1.6) Pub Date : 2024-02-19 A.G. Oreshko, A.A. Oreshko
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Classical Molecular dynamic codes for hot dense plasmas: The BinGo code suite High Energy Density Phys. (IF 1.6) Pub Date : 2024-02-07 A. Calisti, S. Ferri, C. Mossé, B. Talin
The purpose of this paper is to illustrate our contribution to general plasma physics studies obtained since the 90s with multiple versions and adaptations of the classical molecular dynamics (CMD) simulation interactive code called BinGo. After a description of the particulars of the CMD simulation models and the BinGo code suite, some applications are discussed for illustration. These results validate
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Equation of state and Hugoniot of warm dense xenon: Application of average atom-in-jellium model High Energy Density Phys. (IF 1.6) Pub Date : 2024-02-03 Guicun Ma, Jin Qi
In warm dense xenon, thermally excited and pressure-ionized electrons are essential for calculating the equation of state; however, the classical Thomas Fermi model is unsuitable for describing this state. Therefore it is necessary to find an appropriate theoretical model to express the thermal characteristics of electrons in warm dense Xe. In this study, we use the average atom-in-jellium(AJ) model
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Krypton Heβ line spectrum including n=2,3 Li-like satellites with detailed Stark broadened line shapes High Energy Density Phys. (IF 1.6) Pub Date : 2024-02-01 Enac Gallardo-Diaz, Roberto C. Mancini, Jason T. Clapp, Michael Kruse
We discuss the krypton Heβ line spectrum including Li-like satellites with a spectator electron in n=2 and n=3 and detailed line shapes computed using standard Stark broadening theory for hot dense plasma conditions relevant to x-ray tracer spectroscopy of inertial confinement fusion implosion cores. The results show that the interference term in the electron broadening does not produce a significant
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Supersonic radiation wave in doped low density foam High Energy Density Phys. (IF 1.6) Pub Date : 2024-02-01 Avner P. Cohen, Elad Malka, Guy Malamud
Supersonic heat (Marshak) waves in dilute foam are radiation dominated, and play an important role in inertial confinement fusion and in astrophysical and laboratory systems. Doping the foam with heavy metals with high opacity cause dramatic changing of the heat wave behavior by the changing of the material opacity. For that reason, the effects of doping on heat waves propagation in low density foams
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A note on efficiently generating ionic configurations for opacity calculations High Energy Density Phys. (IF 1.6) Pub Date : 2024-01-23 Daniel Aberg, Paul Grabowski, Michael Kruse, Brian G. Wilson
When calculating the spectral opacity of hot dense plasmas one often encounters the need to generate a list of detailed ionic configurations of bound states for each ion stage in the plasma. We present here a non-recursive algorithm for the efficient construction of such a list of states.
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Machine Learning assisted Bayesian inference of mix and Hot-Spot conditions in NIF implosions. High Energy Density Phys. (IF 1.6) Pub Date : 2024-01-22 B.A. HAMMEL, B.D. HAMMEL, H.A. SCOTT, LLNL L. PETERSON
Experiments on the National Ignition Facility (NIF) have provided clear evidence of ablator material mixing into the Hot-Spot, leading to degraded performance. However, inferring the amount of mix and Hot-Spot conditions from typical experimental observations (e.g. x-ray spectra and images) is highly challenging. We have developed an analysis method that utilizes machine learning assisted Bayesian
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Comparison of second-order spectral line widths formulae High Energy Density Phys. (IF 1.6) Pub Date : 2024-01-18 Carlos A. Iglesias, Thomas A. Gomez
Frequently used second-order spectral line width formulae from the projector operator and kinetic theory methods have not been formally compared previously. It is shown that a systematic second-order expansion of the projection operator expression including initial correlations agrees with the second-order kinetic theory result. The agreement assumes a common approximation in the projector operator
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Toward constraint of ionization-potential depression models in a convergent geometry High Energy Density Phys. (IF 1.6) Pub Date : 2024-01-03 D.T. Bishel, P.M. Nilson, D.A. Chin, J.J. Ruby, E. Smith, S.X. Hu, R. Epstein, I.E. Golovkin, J.R. Rygg, G.W. Collins
We demonstrate the value of inner-shell X-ray absorption spectroscopy for dense-plasma atomic physics and explore the coupling between constraint of the thermodynamic state and constraint of ionization-potential depression models. Synthetic K-shell absorption spectra are generated along a radius from a point-like core and analyzed using different ionization-potential depression models. Within this
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The STAG code: A fully relativistic super transition array calculation using Green’s functions High Energy Density Phys. (IF 1.6) Pub Date : 2024-01-02 N.M. Gill, C.J. Fontes, C.E. Starrett
Calculating opacities for a wide range of plasma conditions (i.e. temperature, density, element) requires detailed knowledge of the plasma configuration space and electronic structure. For plasmas composed of heavier elements, relativistic effects are important in both the electronic structure and the details of opacity spectra. We extend our previously described superconfiguration and super transition
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Optical depth measurement of self-reversed line emitted from in-homogenous plasma in laser induced breakdown spectroscopy High Energy Density Phys. (IF 1.6) Pub Date : 2023-11-10 Jalloul Trabelsi, Mounir Esboui, Neïla Terzi
In this work, an original method is proposed and used for measurement of the optical depth of a self-reversed spectral line. A theoretical approach is utilized in an inhomogenous laser induced plasma at local thermodynamic to simulate self-reversed line and then to get the main line profile without self-absorption. The spatial and temporal evolution of optical depth of two spectral lines of Ca II at
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Quantitative proton radiography and shadowgraphy for arbitrary intensities High Energy Density Phys. (IF 1.6) Pub Date : 2023-10-13 J.R. Davies, P.V. Heuer, A.F.A. Bott
Charged-particle radiography and shadowgraphy data can be directly inverted to obtain a line-integrated transverse Lorentz force or a line-integrated transverse refractive index gradient if intensity modulations due to scattering and absorption are negligible, and angular deflections are small. We develop a new direct-inversion algorithm based on plasma physics and compare it to a new Monge–Ampère
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Fast approximation to supershell partition functions: Explicit forms of the coefficients High Energy Density Phys. (IF 1.6) Pub Date : 2023-10-11 Jean-Christophe Pain, Brian G. Wilson
In a previous work, we derived a formula for supershell partition functions, which are the cornerstone of the Super-Transition-Array approach to radiative-opacity calculations. The new expression takes the form of a functional of the distribution of energies within the supershell and allows for fast and accurate computations, truncating the number of terms in the expansion. The latter involves coefficients
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High-precision room temperature Fe opacity measurements at 1000-2000eV photon energies High Energy Density Phys. (IF 1.6) Pub Date : 2023-10-11 Malia L. Kao, Guillaume P. Loisel, James E. Bailey, Patrick W. Lake, Paul D. Gard, Gregory A. Rochau, George R. Burns, William R. Wampler, Haibo Huang, Michael N. Weir
Prior measurements of room temperature (cold) Fe opacity have errors as high as ±10 % and a spread in values that exceeds the uncertainties. These data, along with current cold opacity databases, were used for comparison with experimental solar Fe opacity. The solar Fe opacity is expected to be lower than cold Fe opacity in the ∼1500–2000 eV photon energy range. However, results from this comparison
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Simulation of dissociation effect at high temperature and high pressure by REMC method High Energy Density Phys. (IF 1.6) Pub Date : 2023-10-10 Mingrui Li, Na Feng, Pengfei Gao, Gang Zhou, Chunlin Chen, Bingwen Qian
Considering the zero-point vibration energy of fluid H2, the dissociation process of fluid H2 at different temperatures and densities under 10000 K was studied by using the REMC (reaction ensemble Monte Carlo) method based on classical theory, and the results of different methods were compared and analyzed. The variation of the dissociation degree with temperature predicted by the REMC method is similar
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Observations of multi-ion physics and kinetic effects in a surrogate to the solar CNO reactions High Energy Density Phys. (IF 1.6) Pub Date : 2023-10-10 J. Jeet, A.B. Zylstra, M. Gatu Johnson, N.V. Kabadi, P. Adrian, C. Forrest, V. Glebov
The ‘CNO process’ occurs in heavier stars with finite metallicity in which hydrogen burning is catalyzed in the presence of 12C. These reactions are more strongly dependent on temperature than the pp cycle reactions, and thus the CNO cycle dominates only in massive stars. For these types of reactions to be studied at ICF facilities such as OMEGA, an implosion platform using heavier nuclei in the fuel
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Stimulated Raman side and backscatter instabilities of crossed laser beams in plasma High Energy Density Phys. (IF 1.6) Pub Date : 2023-07-18
Stimulated Raman scattering (SRS) instability due to two nonlinearly coupled laser beams propagating in homogeneous, thermal plasma is analyzed. The temporal evolution equations for pump, scattered and Langmuir waves excited due to the interaction are set up. Using numerical techniques temporal evolution of amplitudes of pump, scattered and resultant Langmuir waves for side and back SRS instabilities
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SpK: A fast atomic and microphysics code for the high-energy-density regime High Energy Density Phys. (IF 1.6) Pub Date : 2023-06-05 A.J. Crilly, N.P.L. Niasse, A.R. Fraser, D.A. Chapman, K.W. McLean, S.J. Rose, J.P. Chittenden
SpK is part of the numerical codebase at Imperial College London used to model high energy density physics (HEDP) experiments. SpK is an efficient atomic and microphysics code used to perform detailed configuration accounting calculations of electronic and ionic stage populations, opacities and emissivities for use in post-processing and radiation hydrodynamics simulations. This is done using screened
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On the transient spatial localization model High Energy Density Phys. (IF 1.6) Pub Date : 2023-03-29 Carlos A. Iglesias
Significant discrepancies relevant to helioseismology between experimental and theoretical photon absorption by plasmas remain unresolved. Interestingly, a new process called transient spatial localization (TSL), where the plasma perturbs the final states in photon ionization processes, ostensibly enhances cross-sections resolving the extant discrepancies. The TSL model, however, is shown to involve
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Schrödinger equation on a generic radial grid High Energy Density Phys. (IF 1.6) Pub Date : 2023-03-17 Christopher Bowen, Jean-Christophe Pain
In this note, we discuss the choice of radial grid in the numerical resolution of the Schrödinger equation. We detail the transformation of the equation resulting from a change of variable and function for a generic radial grid, using either the explicit or implicit form of the relation describing the change of variable, and apply it to the ar+bln(r) log-linear mesh. It is shown that, in the former
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Screening and relativistic effects on the stark broadening of hydrogenic ion lines in a plasma High Energy Density Phys. (IF 1.6) Pub Date : 2023-01-20 D.E. Zenkhri, M.T. Meftah, F. Khelfaoui
In the present work, we compute the amplitude of the real part of the electronic collision operator for the electron broadening of hydrogenic ion lines in plasmas, taking into account the screening effects (the interaction between the free electron (perturber) and the ion (emitter) is governed by Debye potential) and relativistic effects in the dynamics of the perturbing electron. The screening effects
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Atomic structure considerations for the low-temperature opacity of Xenon High Energy Density Phys. (IF 1.6) Pub Date : 2022-12-21 A.J. Neukirch, J. Colgan
We have begun a preliminary investigation into the opacity of Xe at low temperatures (<50 eV). The emissivity and opacity of Xe is a crucial factor in determining the utility of Xe in EUV lithography, with numerous industrial applications. To this end, we have been exploring the accuracy of some approximations used in opacity models for the relevant ion stages of Xe (6 times ionized through 20 times
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Non-equilibrium dissociation rate coefficient of O2+O2 collision at high temperatures High Energy Density Phys. (IF 1.6) Pub Date : 2022-12-05 Huanhuan Zhang, Hong Zhang, XinLu Cheng
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Corrigendum to ultrafast anisotropic disordering in graphite driven by intense hard X-ray pulses High Energy Density Phys. (IF 1.6) Pub Date : 2022-12-05 N.J. Hartley, J. Grenzer, W. Lu, L.G. Huang, Y. Inubushi, N. Kamimura, K. Katagiri, R. Kodama, A. Kon, V. Lipp, M. Makita, T. Matsuoka, N. Medvedev, S. Nakajima, N. Ozaki, T. Pikuz, A.V. Rode, D. Sagae, A.K. Schuster, K. Tono, D. Kraus
Abstract not available
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Withdrawal notice to shock wave implosion in water High Energy Density Phys. (IF 1.6) Pub Date : 2022-12-01 G Chefranov, Ya.E Krasik, A Rososhek
Abstract not available
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Detailed temperature diagnostic studies for Radishock and COAX experiments High Energy Density Phys. (IF 1.6) Pub Date : 2022-11-28 C.L. Fryer, S. Wood, S.X. Coffing, H.F. Robey, C.J. Fontes, H. Johns, P. Kozlowski, T. Urbatsch, N.E. Lanier, D.D. Meyerhofer, T. Byvank
Spectral diagnostics provide a powerful probe of high energy-density physics experiments. By shining an x-ray source on a target, absorption features can be used to determine accurate temperature profiles of that target material. Many studies produce a single temperature/density measurement by fitting these observed spectra. This paper demonstrates how, by leveraging detailed simulations, we can not
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Establishing an isoelectronic line ratio temperature diagnostic for soft X-ray absorption spectroscopy High Energy Density Phys. (IF 1.6) Pub Date : 2022-11-21 T.S. Lane, M.E. Koepke, P.M. Kozlowski, G.A. Riggs, T.E. Steinberger, I. Golovkin
For diagnosing temperatures of high-energy-density plasmas, relying on the ratio of a pair of isoelectronic spectral lines provides the alternative of “matched charge-state transits in different elements” to the more conventional, “unmatched charge-state transits in the same-element” spectral-line-ratio technique. In contrast to a novel previous establishment of isoelectronic emission-line ratio determination
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Note on similarity transform and shock waves High Energy Density Phys. (IF 1.6) Pub Date : 2022-11-14 Chu A. Kwang-Hua
Phase transitions of materials can be investigated by shock compression. It is necessary to obtain the equations governing the shock waves formation. We introduce the similarity variable ξ=r/S(t) for the radial distance r and the radius of the shock front S(t) to handle the continuity equation ∂tρ+∂r(ρv)+2ρv/r=0 for the density ρ(r,t) and for the radial velocity v(r,t) considering a spherically symmetric
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Simulation of non-stationary neon plasma using the THERMOS toolkit High Energy Density Phys. (IF 1.6) Pub Date : 2022-11-13 D.A. Kim, I.Yu. Vichev, A.D. Solomyannaya, A.S. Grushin
The THERMOS toolkit has been improved by adding the module for calculating the properties of non-stationary plasma. Low-density photoionized neon plasma obtained in experiments was simulated. Calculated ion populations, rates of elementary processes, and radiation spectra were compared with results obtained by other scientific groups.
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A fast approximation to supershell partition functions High Energy Density Phys. (IF 1.6) Pub Date : 2022-11-09 Brian G. Wilson, Jean-Christophe Pain
A formula for supershell partition functions, which play a major role in the Super Transition Array approach to radiative-opacity calculations, is derived as a functional of the distribution of energies within the supershell. It consists in an alternative expansion for an arbitrary number of electrons or holes which also allows for quick approximate evaluations with truncated number of terms in the
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The uniform electron gas at high temperatures: ab initio path integral Monte Carlo simulations and analytical theory High Energy Density Phys. (IF 1.6) Pub Date : 2022-11-09 Tobias Dornheim, Jan Vorberger, Zhandos Moldabekov, Gerd Röpke, Wolf-Dietrich Kraeft
We present extensive new Ab initio path integral Monte Carlo (PIMC) simulations of the uniform electron gas (UEG) in the high-temperature regime, 8≤θ=kBT/EF≤128. This allows us to study the convergence of different properties towards the classical limit. In particular, we investigate the classical relation between the static structure factor S(q) and the static local field correction G(q), which is
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Shock wave implosion in water High Energy Density Phys. (IF 1.6) Pub Date : 2022-11-11 S.G. Chefranov, Ya.E. Krasik, A. Rososhek
Analytical modeling of the evolution of cylindrical and spherical shock waves (shocks) during an implosion in water is presented for an intermediate range of convergence, which is not described by the models of self-similar shock propagation far from and in the vicinity of the piston. The model is based on an analysis of the change in pressure and kinetic energy density, as well as on the corresponding
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Optimising point source irradiation of a capsule for maximum uniformity High Energy Density Phys. (IF 1.6) Pub Date : 2022-09-05 Oliver Breach, Peter Hatfield, Steven Rose
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Time-dependent subsonic ablation pressure scalings for soft X-ray heated low- and intermediate-Z materials at drive temperatures of up to 400 eV High Energy Density Phys. (IF 1.6) Pub Date : 2022-08-10 William Trickey, Jamie Walsh, John Pasley
The soft X-ray driven subsonic ablation of five different materials with atomic numbers ranging from 3.5 to 22 is investigated for radiation drive temperatures of up to 400 eV. Simulations were performed using the one-dimensional radiation hydrodynamics simulation code HYADES. For each material, ablation pressure scaling-laws are determined as a function of drive radiation-temperature and time, assuming
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X-ray diffraction measurements of ramp-compressed tin High Energy Density Phys. (IF 1.6) Pub Date : 2022-08-03 EKR Floyd, JM Foster, P Graham, SD Rothman, DR McGonegle, R Penman, JG Turner
X-ray diffraction measurements have been performed on tin ramp compressed at the Orion laser facility to pressures in the range 50 – 100 GPa. The relationship between density and stress that we infer along the adiabat of the tin sample is consistent with previous hydrostatic and quasi-isentropic data and the existence of the BCC phase of tin in this pressure region. Within the limitations of the experimental
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The bands method for tabulating NLTE material properties High Energy Density Phys. (IF 1.6) Pub Date : 2022-08-05 Yechiel Frank, Howard A. Scott
The use of Non-Local Thermal Equilibrium (NLTE) material properties within radiation-hydrodynamic simulations remains a major challenge. The plasma radiative and EOS properties in NLTE can depend on the detailed local radiation field and electron energy distribution. Fully characterizing each of these quantities may require 10’s to 100’s of parameters, making tabulation effectively impossible and requiring
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Time-dependent modeling of photoionization wave propagation in nitrogen High Energy Density Phys. (IF 1.6) Pub Date : 2022-08-03 Zohar Henis, David Salzmann
Photoionization fronts are ubiquitous in astrophysics, but difficult to produce in a laboratory experiment. Recently, it was reported that photoionization fronts may be produced in nitrogen gas at pressure of ten atmospheres irradiated by a radiation source with temperature Tr ∼ 100 eV. We present two computational approaches to describe photoionization propagation in nitrogen gas induced by soft x-rays:
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Preface High Energy Density Phys. (IF 1.6) Pub Date : 2022-06-15 Shinsuke Fujioka
Abstract not available
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Enhancement of high energy X-ray radiography using compound parabolic concentrator targets High Energy Density Phys. (IF 1.6) Pub Date : 2022-04-09 P.M. King, D. Rusby, A. Hannasch, N. Lemos, G. Tiwari, A. Pak, S. Kerr, G. Cochran, I. Pagano, G.J. Williams, S.F. Khan, M. Aufderheide, A. Kemp, S. Wilks, A. Macphee, F. Albert, B.M. Hegelich, M. Downer, A. Mackinnon
We report an increase in MeV energy bremsstrahlung x-ray production using compound parabolic concentrators (CPC) compared to flat solid targets during relativistic laser-plasma experiments on a 140 J, 150 fs laser system using an f/40 focusing optic. CPC enhanced targets show a >3× increase in high energy x-ray production over planar foil targets. This enhancement in x-ray energy spectra shows a direct
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Two-photon ionization in solar opacity experiments High Energy Density Phys. (IF 1.6) Pub Date : 2022-03-29 Michael K.G. Kruse, Carlos A. Iglesias
The discrepancies between theoretical and experimental opacities reported by experiments performed at the Sandia National Laboratory Z-pinch relevant to the solar interior remain unexplained. The suggestion that two-photon ionization could help resolve the discrepancies was recently examined and found not to account for the higher than predicted measured opacities. That test, however, was limited in
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Optimization of a short-pulse-driven Si Heα soft x-ray backlighter High Energy Density Phys. (IF 1.6) Pub Date : 2022-01-13 C. Stoeckl, M.J. Bonino, C.Milehama S.P. Regan, W. Theobald, T. Ebert, S. Sander
High backlighter brightness is important to maximize the number of detected photons in radiography experiments and to minimize the background while backlighting high-energy-density plasmas with strong self-emission. Several different configurations were tested to improve the brightness of the Si Heα x-ray line emission at a photon energy of 1865 eV from high-energy (>1 kJ), short-pulse (∼20 ps), laser-driven
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Real-space Green’s functions for warm dense matter High Energy Density Phys. (IF 1.6) Pub Date : 2021-06-21 M. Laraia, C. Hansen, N.R. Shaffer, D. Saumon, D.P. Kilcrease, C.E. Starrett
Accurate modeling of the electronic structure of warm dense matter is a challenging problem whose solution would allow a better understanding of material properties like equation of state, opacity, and conductivity, with resulting applications from astrophysics to fusion energy research. Here we explore the real-space Green’s function method as a technique for solving the Kohn–Sham density functional
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Trending low mode asymmetries in NIF capsule drive using a simple viewfactor metric * High Energy Density Phys. (IF 1.6) Pub Date : 2021-06-05 B.J. MacGowan, O.L. Landen, D.T. Casey, C.V. Young, D.A. Callahan, E.P. Hartouni, R. Hatarik, M. Hohenberger, T. Ma, D. Mariscal, A. Moore, R. Nora, H.G. Rinderknecht, D. Schlossberg, B.M. Van Wonterghem
The mode-1 x-ray drive asymmetry of indirect-drive Inertial Confinement Fusion(ICF) implosions at the National Ignition Facility(NIF) has been estimated using a simple static ViewFactor model. The model takes as input measured laser performance data in the foot and peak, the hohlraum configuration, and laser to hohlraum pointing. These estimates are compared with neutron time-of-flight measurements
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Laser-induced annihilation: Relativistic particles from ultra-dense hydrogen H(0) High Energy Density Phys. (IF 1.6) Pub Date : 2021-06-05 Leif Holmlid, Sveinn Olafsson
Particle annihilation means that nuclear particles annihilate each other (for example nucleons like a neutron and an anti-neutron) and generate showers of mesons (mainly kaons and pions) at high energy. The kaons decay via pions and muons to electrons, positrons, neutrinos and photons. The energy which can be extracted from the very fast particles is of the order of 50% of the total energy of the nucleon
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MAICRM: A general model for rapid simulation of hot dense plasma spectra High Energy Density Phys. (IF 1.6) Pub Date : 2021-05-17 Xiaoying Han, Lingxiao Li, Zhensheng Dai, Wudi Zheng
This work is the further development of the general model, Multi-Average Ion Collisional-Radiative Model (MAICRM), to calculate the plasma spectral properties of hot dense plasmas. In this model, an average ion is used to characterize the average orbital occupations and the total populations of the configurations at a single charge state. The orbital occupations and population of the average ion are
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A temperature profile diagnostic for radiation waves on OMEGA-60 High Energy Density Phys. (IF 1.6) Pub Date : 2021-05-17 H.M. Johns, C.L. Fryer, S.R. Wood, C.J. Fontes, P.M. Kozlowski, N.E. Lanier, A. Liao, T.S. Perry, J.W. Morton, C.R.D. Brown, D.W. Schmidt, T. Cardenas, T.J. Urbatsch, P. Hakel, J. Colgan, S. Coffing, J. Cowan, D. Capelli, J. Kline
Predicting and matching radiation wave propagation with computational models has proven difficult. Information provided by experiments studying radiation flow has been limited when only radiation breakout is measured. We have developed the COAX (co-axial) diagnostic platform to provide spatial temperature profiles of a radiation wave through low density foams as a more detailed constraint for simulations
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Reducing direct drive preheat with dopants High Energy Density Phys. (IF 1.6) Pub Date : 2021-04-03 T.R. Desjardins, C.A. Di Stefano, E.C. Merritt, K.A. Flippo, F.W. Doss
Preheat in laser-driven experiments can have negative impacts on inertial confinement fusion (ICF) and hydrodynamic experiments. While many groups employ the use of dopants to reduce or block preheat, direct quantification has not previously been explored. We developed a planar platform and a series of ablator targets to measure the electron and x-ray spectra generated by laser-plasma interactions
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Cross-code verification and sensitivity analysis to effectively model the electrothermal instability High Energy Density Phys. (IF 1.6) Pub Date : 2021-02-15 R.L. Masti, C.L. Ellison, J.R. King, P.H. Stoltz, B. Srinivasan
This manuscript presents verification cases that are developed to study the electrothermal instability (ETI). Specific verification cases are included to ensure that the unit physics components necessary to model the ETI are accurate, providing a path for fluid-based codes to effectively simulate ETI in the linear and nonlinear growth regimes. Two software frameworks with different algorithmic approaches
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Comparison of ablators for the polar direct drive exploding pusher platform High Energy Density Phys. (IF 1.6) Pub Date : 2021-02-15 Heather D. Whitley, G. Elijah Kemp, Charles B. Yeamans, Zachary B. Walters, Brent E. Blue, Warren J. Garbett, Marilyn B. Schneider, R. Stephen Craxton, Emma M. Garcia, Patrick W. McKenty, Maria Gatu-Johnson, Kyle Caspersen, John I. Castor, Markus Däne, C. Leland Ellison, Jim A. Gaffney, Frank R. Graziani, John E. Klepeis, Shuai Zhang
We examine the performance of pure boron, boron carbide, high density carbon, and boron nitride ablators in the polar direct drive exploding pusher (PDXP) platform. The platform uses the polar direct drive configuration at the National Ignition Facility to drive high ion temperatures in a room temperature capsule and has potential applications for plasma physics studies and as a neutron source. The
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Results from single-shock Marble experiments studying thermonuclear burn in the presence of heterogeneous mix on the National Ignition Facility High Energy Density Phys. (IF 1.6) Pub Date : 2021-02-15 Thomas J. Murphy, B.J. Albright, M.R. Douglas, T. Cardenas, J.H. Cooley, T.H. Day, N.A. Denissen, R.A. Gore, M.A. Gunderson, J.R. Haack, B.M. Haines, C.E. Hamilton, E.P. Hartouni, Y. Kim, P.M. Kozlowski, M.N. Lee, J.A. Oertel, R.E. Olson, L. Yin
The Marble campaign on the National Ignition Facility investigates the effect of heterogeneous mix on thermonuclear burn for comparison to a probability distribution function (PDF) burn model. Marble utilizes plastic capsules filled with deuterated plastic foam and a fill gas containing tritium. As the capsules implode, the deuterium in the foam mixes with the tritium gas, and DT neutrons are produced
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Simple electron-impact excitation cross-sections including plasma density effects High Energy Density Phys. (IF 1.6) Pub Date : 2021-01-28 Jean-Christophe Pain, Djamel Benredjem
The modeling of non-local-thermodynamic-equilibrium plasmas is crucial for many aspects of high-energy-density physics. It often requires collisional–radiative models coupled with radiative-hydrodynamics simulations. Therefore, there is a strong need for fast and as accurate as possible calculations of the cross-sections and rates of the different collisional and radiative processes. We present an