5.5-7.5 MeV Proton generation by a moderate intensity ultra-short laser interaction with H2O nano-wire targets

We report on the first generation of 5.5-7.5 MeV protons by a moderate intensity short-pulse laser (4.5 \times 1017 W/cm^2, 50 fsec) interacting with H2O nano-wires (snow) deposited on a Sapphire substrate. In this setup, the laser intensity is locally enhanced by the tip of the snow nano-wire, leading to high spatial gradients. Accordingly, the plasma near the tip is subject to enhanced ponderomotive potential, and confined charge separation is obtained. Electrostatic fields of extremely high intensities are produced over the short scale length, and protons are accelerated to MeV-level energies.Comment: submitted to PRL, under press embargo. 6 figure

Evolution of X-pinch loads for pulsed power generators with current from 50 to 5000 kA

A review of X-pinches of various configurations and of different materials as an X-ray source for various applications is presented. The advantages and disadvantages of different designs of X-pinches as a load for generators with a wide range of output parameters and as a source of X-ray radiation for X-ray point-projection imaging were analyzed

Bright, point X-ray source based on a commercial portable 40 ps Nd:YAG laser system

We present some experimental results on X-ray spectra obtained from plasmas produced using a compact Nd:YAG laser system. The beam was focused on different targets (Cu, Al, Ge,…) and both high resolution and low resolution X-ray spectra were recorded

Coherent x-ray radiation induced by high-current breakdown on a ferrite surface

We observe that at the initial stage of a high-current discharge, a low-divergence short x-ray pulse ($\approx\thinspace$$0.5^{\circ}$, $\thinspace$$500$ eV) with the energy of $\sim$$21\mu$J is formed over a ferrite surface, which propagates parallel to the surface in the anode direction. The high directionality of the radiation points to its coherent nature. We propose that the radiation is due to the short-lived magnetization of the ferrite surface excited by a high-power electromagnetic pulse. The radiation is coherent due to the equivalent excitation conditions for all emitters. The excitation pulse and the radiation it generates move at the same speed ($\sim$$c$). Thereby, the emitted waves propagating parallel to the ferrite surface are phase-matched, providing the high radiant intensity of the radiation

Effect of plastic coating on the density of plasma formed in Si foil targets irradiated by ultra-high-contrast relativistic laser pulses

The formation of high energy density matter occurs in inertial confinement fusion, astrophysical, and geophysical systems. In this context, it is important to couple as much energy as possible into a target while maintaining high density. A recent experimental campaign, using buried layer (or "sandwich" type) targets and the ultrahigh laser contrast Vulcan petawatt laser facility, resulted in 500 Mbar pressures in solid density plasmas (which corresponds to about 4.6×107J/cm3 energy density). The densities and temperatures of the generated plasma were measured based on the analysis of X-ray spectral line profiles and relative intensities