Investigation of ultrafast laser-driven radiative blast waves - art. no. 085004

We have examined the evolution of cylindrically symmetric blast waves produ ced by the deposition of femtosecond laser pulses in gas jets. In high-Z ga ses radiative effects become important. We observe the production of an ion ization precursor ahead of the shock front and deceleration parameters belo w the adiabatic value of 1/2 (for a cylinder), an effect expected when the blast wave loses energy by radiative cooling. Despite significant radiative cooling, the blast waves do not appear to develop thin shell instabilities expected for strongly radiative waves. This is believed to be due to the s tabilizing effect of a relatively thick blast wave shell resulting in part from electron thermal conduction effects.