Principal Investigator

Results are presented for research funded under AFOSR contract F49620-76-C0014. This research involved measurements of plasma heating using electron beams, anomalous dc resistivity, and double layers. In addition, the development of a compact x-ray source is being investigated. An extensive set of measurements of the interactions of an electron beam with a collisionless plasma is summarized. It is found that the two stream electron wave decays into a large amplitude ion wave and an electron wave. The ion wave beats with the two stream electron wave and produces a short wavelength electron wave. This beat wave traps and heats the thermal electrons. The efficiency of conversion of beam energy to plasma energy is found to be less than one percent. Steady state anomalous dc resistivity has been investigated in a double plasma device. The spectra of the turbulence and the level of anomalous dc resistivity are in fair agreement with theory. We have constructed another device which will be used to investigate anomalous dc resistivity at much higher currents and electric fields. We have made preliminary measurements of very large amplitude double layer formation in another experiment. Finally, we are constructing a very high power gas puff z pinch. We will measure the time history of x-ray emission from this device