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Abstract. With high-contrast light pulses of 200-fs duration focused
to intensities of
1018W/cm2, strongly coupled plasmas at
solid state density and temperatures of a few 100eV can be generated. These
plasmas are similar to those currently achievable only in indirectly
imploded gas-filled microspheres during stagnation. The table-top size and
high-repetition rate of the lasers producing these ultra-short pulses
provided in our case by the 2-TW facility ATLAS allow to systematically
investigate the basic features of these plasmas. First the mechanism of the
dense-plasma generation is discussed. This is based on hydrocode and PIC
simulations as well as on measurements of light absorption and the energy
transport into the target. We then present spectrally and time-resolved
measurements of the K-shell emission from aluminum targets. By fitting
synthetic spectra obtained from code simulations to the experimental ones,
it can be inferred that the plasma has an electron density of
1024/cm3 and a temperature of
300eV. In the
fast-ignitor concept, a laser-generated electron jet is expected to ignite
the central spot of the compressed target. Using ATLAS pulses focused to
on-target intensities of
1018 - 1019W/cm2, we investigate
the e-beam generation mechanism in preformed under-dense plasmas. A new
fast-electron acceleration mechanism is identified.
IAEA 2001