Exploring higher density regimes using diocotron modes in a toroidal electron plasma

In the Lawrence Non-neutral Torus II (LNT II), a purely toroidal magnetic field (R_o=18 cm, B < 550 G) confines an electron plasma at number densities near 10^7/cm^3. A recently modified filament design has permitted access to higher density regimes for plasma trapped in a 270^^o toroidal arc. Diocotron mode frequencies and damping rates are contrasted with those typical of cylindrical Penning-Malmberg traps. Exploration of these mode damping rates may provide insight into the relative significance of rotational and magnetic pumping transport mechanisms, an overarching goal of the experiment. We also present an improved computational model which will aid in the interpretation of mode damping measurement in LNT II. This work is supported by the National Science Foundation, Grant PHY-1202540.