High Energy Density Physics最新文献

{"title":"Overview of oxygen opacity experiments at the national ignition facility and investigation of potential systematic errors","authors":"D.C. Mayes ,&nbsp;B.A. Hobbs ,&nbsp;R.F. Heeter ,&nbsp;T.S. Perry ,&nbsp;H.M. Johns ,&nbsp;Y.P. Opachich ,&nbsp;M. Hohenberger ,&nbsp;P.A. Bradley ,&nbsp;E.C. Dutra ,&nbsp;C.J. Fontes ,&nbsp;E. Gallardo-Diaz ,&nbsp;M.H. Montgomery ,&nbsp;H.F. Robey ,&nbsp;M.S. Wallace ,&nbsp;D.E. Winget","doi":"10.1016/j.hedp.2025.101177","DOIUrl":"10.1016/j.hedp.2025.101177","url":null,"abstract":"<div><div>Experiments to measure oxygen opacity at stellar interior conditions have been performed at the National Ignition Facility in a Discovery Science campaign. These experiments utilize the Opacity-on-NIF platform with a sample comprised of O, Mg, and Si. The spectral data from the Opacity Spectrometer cover the 1000–2000 eV photon energy range showing bound-free continuum absorption from O and line absorption from Mg and Si. DANTE and the Gated X-ray Detector are employed to measure the sample plasma’s temperature and density, respectively. Initial data show lower transmission than expected by theoretical models, raising questions of whether potential background or data uniformity concerns could produce systematic errors in the inferred transmission. Here, we investigate three concerns thought to be important for the oxygen opacity data, including instrumental scattered background, sample self-emission non-uniformity, and backlight continuum non-uniformity. Additionally, we show the effect of a recently developed method to account for 2nd order crystal reflection. The total effect of these concerns on one experiment is found to be small compared to the observed difference between the inferred transmission and a model calculation at the inferred temperature and density. Thus, we conclude that these potential sources of systematic error cannot account for the observed difference, increasing the likelihood of a real effect due to the high temperature and density conditions. However, because this is only a single experiment, we cannot make a firm conclusion. More experiments measuring the opacity and necessary calibrations are needed to assess the reproducibility and uncertainty of this result.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101177"},"PeriodicalIF":1.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast electron collimation by self-generated magnetic fields at resistivity gradient in imploded plasma","authors":"Yoshinori Ueyama ,&nbsp;Hideo Nagatomo ,&nbsp;Tomoyuki Johzaki ,&nbsp;Hitoshi Sakagami ,&nbsp;Hideaki Habara","doi":"10.1016/j.hedp.2025.101176","DOIUrl":"10.1016/j.hedp.2025.101176","url":null,"abstract":"<div><div>We performed an experiment aiming to demonstrate the collimation of fast electrons by the magnetic field generated at the resistivity gradient in imploded plasma. By using a solid sphere target with an inserted high-Z metal wire, the number of fast electrons reaching the imploded core increased by 93%. The generation of the magnetic field and collimation of fast electrons are confirmed by a two-dimensional Particle-in-Cell simulation using plasma parameters calculated by a radiative hydrodynamic simulation.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"55 ","pages":"Article 101176"},"PeriodicalIF":1.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new approach to include electron interaction effects in super transition array opacity theory","authors":"Daniel Aberg ,&nbsp;Brian G. Wilson ,&nbsp;Jean-Christophe Pain","doi":"10.1016/j.hedp.2025.101175","DOIUrl":"10.1016/j.hedp.2025.101175","url":null,"abstract":"<div><div>A method is presented for the improved calculation of super-shell partition functions which include the repulsive electron–electron interaction energy terms in the Boltzmann factor. Heretofore these interaction terms were approximately treated via the use of Feynman–Jensen inequalities. Such investigations are of particular interest for the super-transition-array approach of hot-plasma radiative opacity.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"54 ","pages":"Article 101175"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143278501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the number of atomic configurations in hot plasmas","authors":"Jean-Christophe Pain ,&nbsp;Daniel Aberg ,&nbsp;Brian G. Wilson","doi":"10.1016/j.hedp.2025.101174","DOIUrl":"10.1016/j.hedp.2025.101174","url":null,"abstract":"<div><div>We propose approximate and accurate formulas for the number of electron configurations in hot plasmas. Such a quantity is an ingredient of algorithms devoted to the generation of configurations or superconfigurations, which is a pre-requisite of opacity calculations. One of the main formulas involves Bessel functions of fractional order and the procedure for improving the accuracy through a series expansion is explained.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"54 ","pages":"Article 101174"},"PeriodicalIF":1.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pseudoatom molecular dynamics plasma microfields","authors":"J.R. White ,&nbsp;C.J. Fontes ,&nbsp;M.C. Zammit ,&nbsp;T.A. Gomez ,&nbsp;C.E. Starrett","doi":"10.1016/j.hedp.2025.101173","DOIUrl":"10.1016/j.hedp.2025.101173","url":null,"abstract":"<div><div>Spectral lines are powerful diagnostic tools for both laboratory and astrophysical plasmas, as their shape is sensitive to the plasma environment. The low-frequency component of the electric microfield is an important input for semi-analytic line broadening codes. In this paper we detail a new method of calculating plasma microfields using configuration-resolved pseudoatom molecular dynamics. This approach accounts for both quantum atomic structure and N-body effects, similar to density functional theory molecular dynamics, but with less computational cost. We present pseudoatom microfields at plasma conditions relevant for recent high energy density laboratory astrophysics experiments conducted at the Sandia Z-Machine, National Ignition Facility, and Linac Coherent Light Source. Compared to established microfield codes we find moderate deviations at solid density conditions and strong agreement at lower plasma densities.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"54 ","pages":"Article 101173"},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-rocket piston model to study three-dimensional asymmetries in implosions at the national ignition facility","authors":"D.T. Casey ,&nbsp;J. Kunimune ,&nbsp;O.A. Hurricane ,&nbsp;O.L. Landen ,&nbsp;P. Springer ,&nbsp;R.M. Bionta ,&nbsp;C.V. Young ,&nbsp;R.C. Nora ,&nbsp;B.J. MacGowan ,&nbsp;J.A. Gaffney ,&nbsp;B. Kustowski ,&nbsp;C. Weber ,&nbsp;A. Kritcher ,&nbsp;J. Milovich ,&nbsp;S. Haan ,&nbsp;M. Gatu Johnson ,&nbsp;D. Schlossberg ,&nbsp;S. Kerr ,&nbsp;P.L. Volegov ,&nbsp;D.N. Fittinghoff ,&nbsp;M. Freeman","doi":"10.1016/j.hedp.2024.101172","DOIUrl":"10.1016/j.hedp.2024.101172","url":null,"abstract":"<div><div>Ignition and gain greater than unity has been achieved in inertial confinement fusion (ICF) implosions at the National Ignition Facility (NIF). These accomplishments required implosions that produced high hotspot pressures that are inertially confined by a dense shell of DT fuel. However, even in the burning and igniting plasma regime, 3D asymmetries can reduce the coupling of shell kinetic energy to the hotspot harming the overall implosion performance and truncating burn. Likewise, the overall scale of the implosion can be minimized by maintaining a high efficiency of energy coupling from the imploding shell to the hotspot. Recent experiments commonly show signs of significant 3D asymmetry that manifest as high hotspot velocity or asymmetry in the self-emission and scattered neutron images. While modeling 3D asymmetries in implosion with full scale hydrodynamic simulations is often performed, it is labor intensive and computationally costly. Therefore, 3D simulation is applied only in special cases like experiments of particular interest. To enable a wider survey of 3D post-shot analysis, an approximate but computationally inexpensive approach is applied by using multiple rocket-pistons discretizing the spherical implosion. These rocket-pistons are coupled together through the central hotspot pressure using the power balance equations. The approach is similar to that reported by Springer [Springer et al., Nuclear Fusion <strong>59</strong> (3) (2019)] with the inclusion of an approximate hohlraum model beginning at the rocket-implosion stage and post-processing of realistic synthetic diagnostic data at the stagnation and peak burn. This rocket piston tool can provide approximate 3D image and diagnostic data that can then be compared quantitively with data enabling new techniques in iterative, forward fitting, and machine learning to interpreting measurements.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"54 ","pages":"Article 101172"},"PeriodicalIF":1.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of external magnetic field inhomogeneity on the nonlinear absorption of intense laser pulse in inhomogeneous warm plasma","authors":"R. Fallah ,&nbsp;R. Khooniki ,&nbsp;A. Esmaeili Karnawah ,&nbsp;H. Golnarkar ,&nbsp;A.R. Niknam","doi":"10.1016/j.hedp.2024.101162","DOIUrl":"10.1016/j.hedp.2024.101162","url":null,"abstract":"<div><div>This paper studies the propagation of an intense laser pulse and the collisional absorption in an inhomogeneous warm plasma by taking into account the external magnetic field inhomogeneity and the ponderomotive force. The calculations are carried out and compared for different magnetic field strengths and their various configurations. For this purpose, using the hydrodynamic equations, the electron density and hence the effective dielectric permittivity of the magneto-active warm plasma are derived and the nonlinear wave equation is solved through the numerical method of Runge–Kutta. The results show that increasing the strength of the external magnetic field causes an increase in the absorption coefficient and the linear magnetic field has a higher influence on the absorption coefficient with respect to the wiggler and constant magnetic fields. Moreover, when the electron temperature increases, the amplitude of the laser field and the absorption coefficient are increased and the spatial damping rate of the laser pulse takes a peak in the plasma. The results also indicate that increasing the energy of the laser pulse causes a decrease in the nonlinear absorption, and the laser energy spatial damping is significantly decreased in contrast to the growth of the amplitude of the laser field. A qualitative comparison of the results indicates that if a linear magnetic field is applied in the same direction of the laser propagation, the collisional absorption rate will be larger with respect to the other magnetic fields. Moreover, the difference in the influence of the mentioned magnetic fields on the collisional absorption increases with increasing the electron temperature and normalized cyclotron frequency and decreases with increasing laser intensity.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"54 ","pages":"Article 101162"},"PeriodicalIF":1.6,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic localized hot spot mix extraction from images in ICF experiments","authors":"Shahab F. Khan,&nbsp;Laurent Divol,&nbsp;Art Pak,&nbsp;Terance Hilsabeck,&nbsp;Bernard Kozioziemski,&nbsp;Benjamin Bachmann,&nbsp;Andrew G. MacPhee,&nbsp;Clement Trosseille","doi":"10.1016/j.hedp.2024.101160","DOIUrl":"10.1016/j.hedp.2024.101160","url":null,"abstract":"<div><div>In Inertial Confinement Fusion Experiments at the National Ignition Facility, time-resolved x-ray images of the central hot spot are captured to diagnose the compression, symmetry and relative amount of mixed material. In this work, we extract bright localized mix features from the images to (1) obtain a more accurate measurement of the hot spot size (compression), (2) match the feature to known capsule defects, and (3) estimate the internal hot spot flow velocity. A new extraction tool was developed that uses derivatives of the size of the hot spot vs contour level to automatically pick out the localized mix features. The size of the “clean” hot spot is larger than that measured with the traditional hot spot analysis routines by 10–30 %. Additionally, since the images are time-resolved, the velocities of the localized mix features can be measured and give an indication of internal flows of the hot spot.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"54 ","pages":"Article 101160"},"PeriodicalIF":1.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of shocks and ablation front in diamond ablator during a capsule implosion experiment at the National Ignition Facility","authors":"Alexandre Do,&nbsp;Eduard L. Dewald,&nbsp;Marius Millot,&nbsp;Christopher R. Weber,&nbsp;Otto L. Landen,&nbsp;Vladimir A. Smalyuk","doi":"10.1016/j.hedp.2024.101161","DOIUrl":"10.1016/j.hedp.2024.101161","url":null,"abstract":"<div><div>An X-ray phase contrast imaging platform using streaked refraction enhanced radiography (RER) was recently developed for capsule implosions at the National Ignition Facility. RER was demonstrated to image in-flight capsule density gradients such as the fuel-ablator interface that is not visible in traditional absorption only radiography. The latest experiments probing the early time evolution of the implosion allowed the precise measurement of the density gradients. An iterative analysis method has been applied to the RER radiograph to allow the reconstruction of temporal evolution of the radial density distribution from the ice-ablator interface to the ablation front. The estimated density reconstruction precision is <span><math><mrow><mo>±</mo><mn>2</mn><mo>.</mo><mn>4</mn><mtext>%</mtext></mrow></math></span> with a density gradient sensitivity threshold of <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>23</mn></mrow></msup><mspace></mspace><msup><mrow><mi>cm</mi></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math></span> over a <span><math><mrow><mn>2</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> scale length. This enabled the study of shocks velocity and density gradients as well as ablation front scale length and shape.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"53 ","pages":"Article 101161"},"PeriodicalIF":1.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FLAIM: A reduced volume ignition model for the compression and thermonuclear burn of spherical fuel capsules","authors":"Abd Essamade Saufi,&nbsp;Hannah Bellenbaum ,&nbsp;Martin Read,&nbsp;Nicolas Niasse,&nbsp;Sean Barrett,&nbsp;Nicholas Hawker,&nbsp;Nathan Joiner,&nbsp;David Chapman","doi":"10.1016/j.hedp.2024.101159","DOIUrl":"10.1016/j.hedp.2024.101159","url":null,"abstract":"<div><div>We present the “First Light Advanced Ignition Model” (FLAIM), a reduced model for the implosion, adiabatic compression, volume ignition and thermonuclear burn of a spherical DT fuel capsule utilising a high-Z metal pusher. <span>FLAIM</span> is characterised by a highly modular structure, which makes it an appropriate tool for optimisations, sensitivity analyses and parameter scans. One of the key features of the code is the 1D description of the hydrodynamic operator, which has a minor impact on the computational efficiency, but allows us to gain a major advantage in terms of physical accuracy. We demonstrate that a more accurate treatment of the hydrodynamics plays a primary role in closing most of the gap between a simple model and a general 1D rad-hydro code, and that only a residual part of the discrepancy is attributable to the heat losses. We present a detailed quantitative comparison between FLAIM and 1D rad-hydro simulations, showing good agreement over a large parameter space in terms of temporal profiles of key physical quantities, ignition maps and typical burn metrics.</div></div>","PeriodicalId":49267,"journal":{"name":"High Energy Density Physics","volume":"53 ","pages":"Article 101159"},"PeriodicalIF":1.6,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}