Tailored blast wave formation: Developing experiments pertinent to laboratory astrophysics

The first production of " tailored" blast waves in a cluster media using an intense, 2 x 10(16) W cm(-2), laser pulse is reported. This new technique produces cylindrical blast waves with a strong axial modulation of variable spatial frequency as a seed for instability growth. Spherical or cylindrical colliding blast waves can also be produced. Energy deposition in the cluster medium was modified using moderate-power (< 10(15) W cm(-2)) " laser-machining," which destroyed clusters in selected regions while keeping the atomic density constant. Electron density profiles track the time evolution showing the production of strongly modulated blast waves and the development of a thin shell after approximate to 6 ns in H-2. Similarity parameters suggest that the hydrogen results are hydrodynamically scalable, but instabilities are precluded by the lack of radiation and low Reynolds number. Similar argon and xenon experiments do not form blast waves on the studied time scale, but indicate that radiation might become influential later in the evolution. (c) 2005 American Institute of Physics.