Collisionless shockwave generation in counter-streaming plasmas using Gekko XII HIPER laser

Collisionless shock wave generation in counter-streaming plasmas for several target materials (Al, C, Cu, and Pb) is investigated using a high-power laser system. Counter-streaming plasmas are produced by irradiating an inner surface of a double-plane target. For Al, C, and Pb, a shock wave is observed in self-emission measurements similar to the previous experiment using a CH target [Y. Kuramitsu et al., J. Phys.: Conf. Series. 24, 042008 (2010)], and the width of the transition region is much shorter than the ion-ion collision mean-free-paths. The mean-free-paths tend to be longer for heavier materials, because the ionization degrees Z are not so different among these materials.