666 research outputs found
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 (,
eV) with the energy of
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 (). 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
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