Reversed scheme of thin foil acceleration

Abstract

An alternative concept for accelerating thin foils to high velocity has been proposed and tested. The thin (10 μm) Al foil has been accelerated by the ablative plasma generated by means of the third harmonic (λ=0.438 μm, τ=250 ps) of the iodine laser pulse of the energies of 75 and 190 J irradiating a massive Cu target. Two separation distances of the foil from the massive target of 100 and 500 μm were used. It has been shown that this method of an indirect, two-step acceleration, named as the reversed acceleration scheme, can be more effective than the classic, direct-drive approach. The Al flyer foil has reached a velocity of ∼1.3×107 cm/s, i.e., significantly higher than that in the comparable “classic” ablative acceleration experiment.