Neutral gas filled transport cells for high current electron beams

Summary form only given. A series of experiments is being conducted with a passive electron beam transport and centering system consisting of a conducting tube filled with neutral gas. The object is to study the transport and centering properties of the cell as a function of input beam current, transport cell length, cell diameter, fill pressure, and fill gas type. The electron beam is generated by the US Naval Research Laboratory's SuperIBEX accelerator, which produces a 5.0-MeV, 50-kA, 40-ns FWHM (full width at half maximum) electron beam. The electron beam diode consists of a 6-mm-diameter cold cathode and a 0.5-mil-thick titanium foil anode. The injected beams are l2.0 cm in diameter and have low divergence (l50 mrad). The experiments cover a wide range of parameters. The beam current is varied from 10 to 40 kA, the pressure from 0 to 100 mtorr, the transport length from 40 to 120 cm, and the cell diameter from 5 to 10 cm, and several gases (Ar, He) are used to examine the effects of ionization potential. The results of the experiments have been compared to computer simulations of SuperIBEX beams in the gas-filled transport cells