Double Potential Well Regimes in Collisionless Spherical Discharges

The study of potential profiles in glow discharges initiated between concentric spherical electrodes is motivated by the experimental investigations of inertial electrostatic confinement devices, which have the potential to be used as compact neutron generators. Here, we explore double potential well regimes within the cathode of such devices, utilizing a previously developed collisionless model. This is accomplished in an efficient manner by creating contour plots of the double well depth (DWD) and the double well radius, "width," with respect to the spreads in angular energy of electrons and ions, and with respect to the ion perveance and ratio of ion to electron perveance. These plots expand our knowledge of the DWD behavior beyond the previous understandings, both qualitatively and quantitatively. In addition, we consider the relationship of these results with the experimental results of Gu and Miley and the theoretical results of Matsuura in an effort to better understand the results of Gu and Miley