Experimental evidence of the generation of multi-hundred megabar pressures in 0.26 μm wavelength laser experiments

Abstract

A 9 (im thick aluminium foil is accelerated to a velocity of about 160 km/s by a laser of 0-26 ^m wavelength and intensity of 10 15 W/cm 2 and collides with an aluminium impact foil. The measurement of the velocity of the induced shock wave in the impact foil, using a step method at the rear of the impact foil, gives pressures in the multi-hundred megabar range. The dynamics and constraints of this shock wave are presented and the effect of X-ray preheating, which can be important at this laser wavelength, is discussed.

Experimental investigation of flyer character driven by a laser and increasing pressure with the flyer technique

“…In the experimental study of the equation of state using laser-driven shocks, 1-9 the laser-driven flyer technique has been employed routinely [10][11][12][13] due to its effects of notable pressure increase and better control of target preheating produced by the superthermal electron. But the reliability and correctness of experimental results obtained by use of this technique depend on whether the planar and steady shock wave can be formed in the target impacted by the flyer, which was in turn determined by flyer characters such as velocity, density, etc.…”

Recent advances in laser–plasma experiments using foams

“…In passing, we notice that the impedance-matching technique was used largely in the past to intensify laser-driven shock waves~Obenschain et al, 1983;Fabbro et al, 1986;Faral et al, 1990!. Such effect can be maximized by using low density foams before the laser target, as seen in the previous section. before the target material.…”

Generation of ultra-high-pressure shocks by collision of a fast plasma projectile driven in the laser-induced cavity pressure acceleration scheme with a solid target

“…1,3,[8][9][10][11][12][13][14][15] The highest pressures, up to Gbar and possibly beyond, can, potentially, be produced by nuclear explosions and laser-based methods. In general, requirements for the shock properties are different for different domains of the shock applications.…”

“…Generation of strong shocks by using lasers is feasible by direct irradiation of a solid target with a laser beam (a) 1,3,8,14,15 or the soft X-ray flux produced by the laser (b), 3,12,13 as well as by collision of a projectile (flyer foil) driven by the laser beam (c) 9,10 or the X-ray flux (d) 3,11 with a solid target. A significant advantage of the methods (c) and (d) relative to (a) and (b) is the lack (or a small level) of preheating of the shock-compressed material, which considerably facilitates determining the EOS of the material.…”