Intense Pulsed Ion Beam Neutralization Focusing and Collective Plasma Interactions.

摘要

The purpose of this thesis is to study the propagation of an intense pulsed ion beam in certain environments. Three areas of ion beam propagation are studied: charge and current neutralization by electrons when a beam is injected into a vacuum region; focusing of a beam when it is axially injected into a solenoidal magnetic lens; and collective interactions when a beam passes through a background hydrogen plasma. The experimentally observed beam behavior in each of these situations is analyzed and compared with theoretical models. In the experiment, a beam (360 keV., 65 amps/sq cm, 150 ns.) was extracted from a planar, magnetically insulated diode and injected into a field free vacuum region. The beam was found to be both charge and current neutralized by electrons drawn axially into the beam from the cathode of the diode. The neutralization process was modelled with a theory which predicts the velocity distribution of the comoving neutralizing electrons. (jhd)