Introduction to High-Energy-Density Physics

Drake, R. P.

doi:10.1007/3-540-29315-9_1

Cited by 177 publications

(84 citation statements)

References 13 publications

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“…3; the plateau is less marked at higher density. This plateau effect is clearly related to the TFD ionization relation with temperature, but is also reminiscent of simple scaling laws at low density in the Saha regime (the well known scaling law Z * = 20 √ T KeV [17] is a simplification of Saha equations [18]). The plasma described by OFMD is clearly strongly screened and electrons are degenerate at low temperature (θ = T /T F = 0.28 at 10 eV) but quasi-classical at high temperature (θ = 31 at 5000 eV).…”

Section: Effective One Component Plasmamentioning

confidence: 89%

Behavior of the coupling parameter under isochoric heating in a high-Zplasma

et al. 2013

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The ion-ion coupling parameter Γ is estimated for tungsten along the ρ=40 g/cm 3 isochore corresponding to twice the normal density with temperatures ranging from 10 eV to 5 keV. Using a variety approaches from a spherical Thomas-Fermi ion to a full three-dimensional orbital-free method, we show that along an isochore the effective ionic coupling parameter is almost constant over a wide range of temperatures (in our case Γ 20) due to the competition between rising temperatures and increased ionization. This Γ plateau effect depends on the chosen density and is well delineated at normal density but almost disappears at five times the normal density. This effect could be used to obtain well defined and predictable experimental conditions.

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Section: Effective One Component Plasmamentioning

confidence: 89%

Behavior of the coupling parameter under isochoric heating in a high-Zplasma

et al. 2013

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“…1b, indicated by the open arrows). Figure 2 shows the measured Au-wall plasma-fill gas interface radius as a function of time compared with the sound speed [C s ∝ (ZT e m i -1 ) 1/2 ] that sets the scale for hydrodynamic rarefaction expansion in vacuum [11,12]. The expansion speed of the Au blow-off is estimated to be ~ (2.1± 0.3)×10 7 cm s -1 , which is slower than C s ~ 2.5×10 7 cm s -1 , indicating that the wall blow-off expansion has been compressed by the fill gas [13].…”

mentioning

confidence: 99%

Impeding Hohlraum Plasma Stagnation in Inertial-Confinement Fusion

Séguin

Frenje

et al. 2012

Phys. Rev. Lett.

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“…ce is the electron gyrofrequency and is the collision time [10,11]. E fields may modify the plasma conditions and, if sufficiently large, could enhance thick-target bremsstrahlung at x-ray energies well above the Planckian background.For low-intensity laser drive, such as used in most hohlraum experiments [1][2][3][4][5][6][7][8][9], the dominant source for B-field generation is expected to be nonparallel electron density (n e ) and temperature (T e ) gradients (rn e Â rT e ) [10,11]. The E field is expected to result from electron pressure gradients (rP e ) [10,11].…”

mentioning

confidence: 99%

Observations of Electromagnetic Fields and Plasma Flow in Hohlraums with Proton Radiography

Séguin

Frenje

et al. 2009

Phys. Rev. Lett.

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We report on the first proton radiography of laser-irradiated hohlraums. This experiment, with vacuum gold (Au) hohlraums, resulted in observations of self-generated magnetic fields with peak values $10 6 G. Time-gated radiographs of monoenergetic protons with discrete energies (15.0 and 3.3 MeV) reveal dynamic pictures of field structures and plasma flow. Near the end of the 1-ns laser drive, a stagnating Au plasma ($10 mg cm À3 ) forms at the center of the hohlraum. This is a consequence of supersonic, radially directed Au jets ($1000 m ns À1 , $Mach 4) that arise from the interaction of laser-driven plasma bubbles expanding into one another. A high-Z enclosure, i.e., hohlraum, creates an environment filled with a nearly blackbody (Planckian) radiation field when irradiated by high-power lasers or energetic ions [1,2]. The cavity generates intense thermal x rays at a radiation temperature (T r ) of hundreds of eV. Hohlraums have been extensively used as radiation sources or platforms for a wide range of basic and applied physics experiments. In studies of laboratory astrophysics and highenergy-density (HED) physics [3,4], for example, hohlraums are used for creating and simulating various extreme HED conditions, including those of stellar and planetary interiors. The hohlraum radiation field is used to compress spherical capsules, through capsule ablation, to high temperature and density in indirect-drive inertial confinement fusion [1,2].The use of hohlraums requires an understanding of physics details, such as coupling efficiency, plasma conditions, instabilities, radiation uniformity [1,2,5,6], and cavity shape [1,2,7,8]. Electric (E) and magnetic (B) fields generated by several processes may have important effects on hohlraum physics and overall performance [9]. B fields inside a hohlraum can reduce heat flow, since cross field thermal conductivity is modified by a factor of ð1 þ ! 2 ce 2 Þ À1 , where ! ce is the electron gyrofrequency and is the collision time [10,11]. E fields may modify the plasma conditions and, if sufficiently large, could enhance thick-target bremsstrahlung at x-ray energies well above the Planckian background.For low-intensity laser drive, such as used in most hohlraum experiments [1][2][3][4][5][6][7][8][9], the dominant source for B-field generation is expected to be nonparallel electron density (n e ) and temperature (T e ) gradients (rn e Â rT e ) [10,11]. The E field is expected to result from electron pressure gradients (rP e ) [10,11]. Despite such expectations, prior to this work, no direct experimental measurement and characterization of such hohlraum fields have been made.The first observations of E and B fields and their evolution in hohlraums, made with time-gated monoenergetic proton radiography [12], are presented in this Letter. Coupled plasma flow dynamics were also observed. Simultaneous imaging with two discrete proton energies breaks any inherent degeneracy between E and B.In the radiography setup (Fig. 1) the backlighter is a D 3 He-filled, thin-glass-shell targe...

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Introduction to High-Energy-Density Physics

Cited by 177 publications

References 13 publications

Behavior of the coupling parameter under isochoric heating in a high-Zplasma

Behavior of the coupling parameter under isochoric heating in a high-Zplasma

Impeding Hohlraum Plasma Stagnation in Inertial-Confinement Fusion

Observations of Electromagnetic Fields and Plasma Flow in Hohlraums with Proton Radiography

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