Development of a long pulse plasma gun discharge for magnetic turbulence studies

A long pulse ($\approx 300~\mu s$) plasma gun discharge is in development at the Bryn Mawr College Plasma Laboratory for the production of sustained magnetized plasma injection for magnetohydrodynamic (MHD) turbulence studies. An array of eight $0.5~mF$ parallel capacitors are used to create a pulse-forming-network (PFN) with a plateaued current output of $\approx 50~kA$ for at least $200$ of the $300~\mu s$ pulse. A $24~cm$ inner diameter plasma gun provides stuffing flux fields at the stuffing threshold in order to allow for the continuous injection of magnetic helicity. Plasma is injected into a $24~cm$ diameter flux-conserving aluminum chamber with a high density port array for fine spatial resolution diagnostic access. Fluctuations of magnetic field and saturation current are measured using pickup probes and Langmuir probes respectively.