Collective Acceleration of Laser Produced Ions

Experimental studies of the collective acceleration of laser produced ions have been conducted. An intense relativistic electron beam (1 MeV, 30 kA, 30 ns) is emitted from a 4 mm diameter tungsten cathode and passes through a 2.4 cm hole in a stainless steel anode into a 14 cm diameter downstream drift tube. Ions are provided on the downstream side of the anode plane by firing a 4-10 J, 15 ns Q-switched ruby' laser pulse at solid or foil targets mounted on the downstream side of the anode plane. Accelerated ion energies are measured using time of flight and range energy/track etching techniques. Ion charge states are measured using an EIB Thomson spectrometer. Results will be compared with measurements of the pre-acceleration characteristics of the laser produced ions from these target geometries obtained using an electrostatic analyzer.