Microwave scaling of laser plasma interactions. Final report

The limitations of previous target plasmas and the requirements for improved target plasmas are discussed. Two distinctly different approaches were pursued successfully. The first approach represents a relatively minor modification of the discharge techniques previously used in the QUIPS facility. Utilizing a combination of the pulsed rf plasma production techniques developed under the previous year's contract with a new pulsed magnetic field technique, we have produced a target plasma possessing all of the desirable properties of previous target plasmas, with an order of magnitude higher fractional ionization and improved boundary conditions. The second target plasma production technique is based on plasma production by intense, short pulse laser irradiation of a solid target. The resulting blowoff plasma expands into vacuum and, after a suitable delay time, is irradiated by a pulsed mirowave beam. The blowoff plasma properties and preliminary results of microwave interaction experiments are described.