With the advent of high-energy-density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, millimeter-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors, equations of state relevant to planetary interiors, strong shock-driven nonlinear hydrodynamics and radiative dynamics relevant to supernova explosions and subsequent evolution, protostellar jets and high Mach number flows, radiatively driven molecular clouds and nonlinear photoevaporation front dynamics, and photoionized plasmas relevant to accretion disks around compact objects such as black holes and neutron stars.

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Experimental astrophysics with high power lasers and Z pinches

▪ Abstract We know that giant planets played a crucial role in the making of our Solar System. The discovery of giant planets orbiting other stars is a formidable opportunity to learn more about these objects, what their composition is, how various processes influence their structure and evolution, and most importantly how they form. Jupiter, Saturn, Uranus, and Neptune can be studied in detail, mostly from close spacecraft flybys. We can infer that they are all enriched in heavy elements compared to the Sun, with the relative global enrichments increasing with distance to the Sun. We can also infer that they possess dense cores of varied masses. The intercomparison of presently characterized extrasolar giant planets shows that they are also mainly made of hydrogen and helium, but that they either have significantly different amounts of heavy elements, have had different orbital evolutions, or both. Hence, many questions remain and need to be answered to make significant progress on the origins of planets...

THE INTERIORS OF GIANT PLANETS: Models and Outstanding Questions

Hydrogen and helium are the most abundant elements in the Universe. They are also, in principle, the most simple. Nonetheless, they display remarkable properties under extreme conditions of pressure and temperature that have fascinated theoreticians and experimentalists for over a century. Advances in computational methods have made it possible to elucidate ever more of their properties. Some of these methods that have been applied in recent years, in particular, those that perform simulations directly from the physical picture of electrons and ions, such as density functional theory and quantum Monte Carlo are reviewed. The predictions from such methods as applied to the phase diagram of hydrogen, with particular focus on the solid phases and the liquid-liquid transition are discussed. The predictions of ordered quantum states, including the possibilities of a low- or zero-temperature quantum fluid and high-temperature superconductivity are also considered. Finally, pure helium and hydrogen-helium mixtures, the latter which has particular relevance to planetary physics, are discussed.

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The properties of hydrogen and helium under extreme conditions

Relativistic high-power laser–matter interactions

I review the origin and properties of electromagnetic fields produced in heavy-ion collisions The field strength immediately after a collision is proportional to the collision energy and reaches &#x7e; at RHIC and &#x7e; at LHC I demonstrate by explicit analytical calculation that after dropping by about one-two orders of magnitude during the first fm/c of plasma expansion, it freezes out and lasts for as long as quark-gluon plasma lives as a consequence of finite electrical conductivity of the plasma Magnetic field breaks spherical symmetry in the direction perpendicular to the reaction plane, and therefore all kinetic coefficients are anisotropic I examine viscosity of QGP and show that magnetic field induces azimuthal anisotropy on plasma flow even in spherically symmetric geometry Very strong electromagnetic field has an important impact on particle production I discuss the problem of energy loss and polarization of fast fermions due to synchrotron radiation, consider photon decay induced by magnetic field, elucidate dissociation via Lorentz ionization mechanism, and examine electromagnetic radiation by plasma I conclude that all processes in QGP are affected by strong electromagnetic field and call for experimental investigation

https://downloads.hindawi.com/journals/ahep/2013/490495.pdf

Particle production in strong electromagnetic fields in relativistic heavy-ion collisions

Hugoniot points of liquid ${\mathrm{D}}_{2}$ were measured at shock pressures of 107, 54, and $28\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$ using converging explosively driven systems (CSs). The two data sets measured with a laser $(L)$ and pulsed currents (PCs) differ substantially. Our results are in excellent agreement with the PC data and the error bars of the CS-PC data are less than half those of the $L$ data. The limiting compression obtained from the best fit to the CS-PC data is $4.30\ifmmode\pm\else\textpm\fi{}0.10$ at $100\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. The CS-PC data are in good agreement with path integral Monte Carlo and density functional theory calculations, which is expected to be the case at even higher shock temperatures and pressures, as well.

Shock compression of liquid deuterium up to 109 GPa

Experimental data on the compression of solid deuterium at a pressure of ∼60 GPa are presented. The data were obtained on a generator of powerful converging spherical shock waves. The results are compared with the data of shock experiments obtained on a Nova laser facility and an electrodynamic EPBF-Z plant.

Shock compression of solid deuterium

A brief review of the achievements on ultra-high magnetic field generation at VNIIEF is given. The cascade MC-1 generators for the 10 and 20 MG magnetic field ranges are described. Investigations in ultra-high fields provided by cascade MC-1 generators are an example of extended international collaboration.

VNIIEF achievements on ultra-high magnetic fields generation

The multimegagauss magnetic fields MC-1-generator in the form of several coaxial liners made of material with controlled conductivity and enveloped in a HE ring is described. The generator is characterized by exceptional reproducibility of initial and final parameters, is produced in series, is easy and simple in arrangement for experiments at any firing test-sites. Use of this generator for the study of properties of substance at the upper limit in magnetic field range known to the science is suggested and can be a basis for a broad international collaboration of specialists in ultrahigh magnetic field production and application.

The cascade magnetocumulative generator of ultrahigh magnetic fields — A reliable tool for megagauss physics

The magnetic susceptibility and conductivity of single-crystal iron monosilicide are investigated in ultrahigh magnetic fields up to 450 T at a temperature of 77 K. It is found that the conductivity of iron monosilicide increases continuously by two orders of magnitude as the magnetic field increases. The results obtained can be interpreted as a semiconductor-metal transition induced by the magnetic field. The dependence of the conductivity on the magnetic field is described well on the basis of the spin-fluctuation theory.

A. I. Bykov

Papers

Shock compression of liquid deuterium up to 109 GPa

Shock compression of solid deuterium

VNIIEF achievements on ultra-high magnetic fields generation

The cascade magnetocumulative generator of ultrahigh magnetic fields — A reliable tool for megagauss physics

Semiconductor-metal transition in FeSi in ultrahigh magnetic fields up to 450 T