Basic properties of generation of high-current ion beams using the
skin-layer ponderomotive acceleration (S-LPA) mechanism, induced by a
short laser pulse interacting with a solid target are studied. Simplified
scaling laws for the ion energies, the ion current densities, the ion beam
intensities, and the efficiency of ions' production are derived for
the cases of subrelativistic and relativistic laser-plasma interactions.
The results of the time-of-flight measurements performed for both
backward-accelerated ion beams from a massive target and
forward-accelerated beams from a thin foil target irradiated by 1-ps laser
pulse of intensity up to ∼ 1017 W/cm2 are
presented. The ion current densities and the ion beam intensities at the
source obtained from these measurements are compared to the ones achieved
in recent short-pulse experiments using the target normal sheath
acceleration (TNSA) mechanism at relativistic (>1019
W/cm2) laser intensities. The possibility of application of
high-current ion beams produced by S-LPA at relativistic intensities for
fast ignition of fusion target is considered. Using the derived scaling
laws for the ion beam parameters, the achievement conditions for ignition
of compressed DT fuel with ion beams driven by ps laser pulses of total
energy ≤ 100 kJ is shown.
Beam-Halo Measurements in High-Current Proton Beams