Gigabar Spherical Shock Generation on the OMEGA Laser

Abstract

This Letter presents the first experimental demonstration of the capability to launch shocks of several-hundred Mbar in spherical targets--a milestone for shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)]. Using the temporal delay between the launching of the strong shock at the outer surface of the spherical target and the time when the shock converges at the center, the shock-launching pressure can be inferred using radiation-hydrodynamic simulations. Peak ablation pressures exceeding 300 Mbar are inferred at absorbed laser intensities of ∼3×10(15) W/cm2. The shock strength is shown to be significantly enhanced by the coupling of suprathermal electrons with a total converted energy of up to 8% of the incident laser energy. At the end of the laser pulse, the shock pressure is estimated to exceed ∼1 Gbar because of convergence effects.

Energy Penetration into Arrays of Aligned Nanowires Irradiated with Relativistic Intensities: Scaling to Terabar Pressures

“…However, the creation of matter in this regime in the laboratory has been limited to the central hot spot of the spherically imploded capsule in inertial confinement fusion experiments conducted using the world's highestenergy lasers (8,9). The ability to create UHED matter using smaller facilities is thus of great interest to make this extreme plasma regime more accessible for fundamental studies and applications.…”

Ab initioquantum Monte Carlo simulations of the uniform electron gas without fixed nodes: The unpolarized case

“…In particular, recent experimental progress with highly compressed matter [1][2][3] such as plasmas in laser fusion experiments [4][5][6][7][8][9] and solids after laser irradiation [10], but also the need for an appropriate description of compact stars and planet cores [11][12][13], has lead to a high demand for accurate simulations of electrons in the warm dense matter (WDM) regime. Unfortunately, the application of all QMC methods to fermions is severely hampered by the fermion sign problem (FSP) [14,15].…”

Ab initio results for the static structure factor of the warm dense electron gas

“…[1] In addition to astrophysical applications such as planet interiors [2,3] and white dwarf atmospheres, such extreme conditions are now routinely created in the lab, for example, in experiments with laser excited solids [4] or inertial confinement fusion. [5][6][7] Despite this remarkable experimental progress, a rigorous theoretical description remains notoriously difficult due to the simultaneous presence of three physical effects: (a) strong electronic excitations, (b) Coulomb coupling effects, and (c) fermionic exchange. This is typically expressed by two parameters being of the order of unity: the degeneracy temperature = k B T/E F (with E F = k F 2 /2 and k F = (9 /4) 1/3 /r s being the Fermi energy and wave vector, respectively) and the Brueckner (coupling) parameter r s = r∕a B with r and a B being the mean interparticle distance and Bohr radius, respectively.…”