EXPERIMENTS ON THE INTERACTION OF FAST HEAVY-IONS WITH A LASER-PLASMATARGET

We have experimentally investigated the stopping power of a laser-abla ted carbon plasma tested with a 225 keV/u oxygen beam. A dense plasma target was produced by irradiation of a graphite rod with a Q-switched Nd-glass laser. We have developed a diagnostics system for the target plasma using laser interferometry. The motion of the fringes was obse rved by a streak camera in order to obtain time-dependent electron den sity profiles. The maximum areal electron density of the carbon plasma reached n(e)l = 1 x 10(18) cm(-2). For the measurement of the energy loss of ions in the target, we developed a time-resolved magnetic spec trometer system with a plastic scintillator and an MCP. Using a streak camera we measured the shift of the beam spot on the MCP. The stoppin g power observed 40 ns after the laser was fired was 15 MeV/(mg/cm(2)) . This value is enhanced by 50% compared to that in the cold equivalen t. (C) 1998 Elsevier Science B.V. All rights reserved.