Diverging ion motion in an inertial electrostatic confinement discharge

An inertial electrostatic confinement device operating in the gaseous discharge pressure regime (units to tens of mTorr) is shown to consist of a substantial flux of neutrals diverging from the cathode center. Using Doppler shift spectroscopy, it is shown that directional ion beams, originating from the center, increase in energy as they move away from the center. Moreover, through charge exchange, these ions become energetic neutrals and travel out of the cathode to the anode. Although naturally there are converging ions, it is shown that this is a lesser component of the energetic particle beams in this pressure range.