1,502 research outputs found
"Single-cycle" ionization effects in laser-matter interaction
We investigate numerically effects related to ``single-cycle'' ionization of
dense matter by an ultra-short laser pulse. The strongly non-adiabatic response
of electrons leads to generation of a megagauss steady magnetic field in
laser-solid interaction. By using two-beam interference, it is possible to
create periodic density structures able to trap light and to generate
relativistic ionization frontsComment: 12 pages, 6 figures, to be published in Laser and Particle Beam
Fast magnetic reconnection in laser-produced plasma bubbles
Recent experiments have observed magnetic reconnection in
high-energy-density, laser-produced plasma bubbles, with reconnection rates
observed to be much higher than can be explained by classical theory. Based on
fully kinetic particle simulations we find that fast reconnection in these
strongly driven systems can be explained by magnetic flux pile-up at the
shoulder of the current sheet and subsequent fast reconnection via two-fluid,
collisionless mechanisms. In the strong drive regime with two-fluid effects, we
find that the ultimate reconnection time is insensitive to the nominal system
Alfven time.Comment: 5 pages, 4 figures, accepted by Phys. Rev. Let
Absorption of Ultrashort Laser Pulses in Strongly Overdense Targets
We report on the first absorption experiments of sub-10 fs high-contrast
Ti:Sa laser pulses incident on solid targets. The very good contrast of the
laser pulse assures the formation of a very small pre-plasma and the pulse
interacts with the matter close to solid density. Experimental results indicate
that p-polarized laser pulses are absorbed up to 80 percent at 80 degrees
incidence angle. The simulation results of PSC PIC code clearly confirm the
observations and show that the collisionless absorption works efficiently in
steep density profiles
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