Recent Experiments with Toroidal Pure-Electron Plasma -- Trivelpiece-Gould Modes, Diocotron Mode Damping, and Asymmetry Modes in the Lawrence Non-neutral Torus II

Electron plasma is confined using a purely toroidal magnetic field ($R_{o}=$ 18 cm, $B$ \textless\ 550 G) for times ($\sim$ 1 s) that are much longer than any of the dynamical timescales of the system. The Lawrence Non-Neutral Torus II (LNT II) can be operated as a partial torus in which plasma is confined in C-shaped toroidal sectors or as a fully toroidal, closed field trap. We present results of recent wave excitation and damping studies in LNT II, including the first observations of Trivelpiece-Gould waves in toroidal electron plasma, measurements of the dependence of the $m=$1 diocotron mode damping rate on magnetic field, plasma position, and neutral pressure, and first observations of asymmetry modes in a toroidal electron plasma. Efforts are also underway to enhance the magnetic field strength and augment the diagnostic capabilities of the apparatus. This work is supported by the National Science Foundation -- Award {\#}1202540.