Washer-Gun Plasma Source for Magnetic Reconnection Experiments on VTF

We present a recently built electrostatic washer-gun plasma source for the Versatile Toroidal Facility (VTF). The source produces plasmas with estimated densities of $\sim10^{19}$ m$^{- 3}$ and electron temperatures of $\sim 5-20$ eV. The present plasma source for VTF is microwave-induced electron cyclotron resonant breakdown and requires a strong toroidal magnetic field, which acts as a guide field in reconnection experiments. The gun will allow reconnection experiments with no guide field. The source is based on the design developed by Sterling Scientific [1, 2]. To operate, gas is injected into a channel formed by a stack of alternating molybdenum and boron nitride washers with a molybdenum electrode washer at each end. A capacitor bank is discharged through these electrodes and the gas. The resulting plasma escapes the channel into the main chamber of the experiment. If available, we will present data on argon plasma produced by the gun inside the VTF. \\[1ex] [1] G.~Fiksel, et al., Plasma Sources Sci. Technol., {\bf 5}, 78 (1996)\\[0ex] [2] D.~Hartog et al., Plasma Sources Sci. Technol., {\bf 6}, 492 (1997)