Development of a plasma gun for forming and launching a magnetized target plasma

We present the engineering design of a coaxial plasma gun, its components and subsystems, for creating a high-b ($\beta\gt \gt 1$) magnetized target plasma for Plasma-Jet driven Magneto-Inertial Fusion approach (PJMIF). It is envisaged that the target plasma with a high initial temperature ($\gt 50 \mathrm{eV}$) will be formed by the head-on collision of two opposing conical arrays of magnetized plasmoids launched by multiple copies of the plasma gun. The technical details of the formation of the plasmoid inside the plasma gun is described in the companion paper presented in this Conference [1]. This first generation high- $\beta$ target plasma gun (HiBG1) is composed of three major components (bias field system, gas valve and a six-path spark gap switch). The bias field system is designed to create a strong pulsed magnetic field ($\mathrm{B}\gt 1 \mathrm{~T}$) inside the electrodes where the pre-ionized plasma is. The fast gas valve is used to inject a working gas at the breech of the gun. While for fusion application, the working gas is the fusion fuel (deuterium and tritium), helium gas will be used as their surrogate for the development of the HiBG1 plasma gun. After the working gas is injected, it will be pre-ionized and allowed to further expand up to the top of bias field coil. The main discharge current (200-300 kA) is turned on with a six-path, low inductance spark gap switch. When the three described components are precisely controlled, HiBG1 is expected to produce a spheromak-like plasmoid with $ne \gt 10^{21} / {m} 3, T e\gt 1 \ {eV}, {v}\gt 100 \ {km} / {s}$ and embedded magnetic field $\gt 0.1 T$. The detail design of the control system for the proper sequencing and control of these operations will be presented. The diagnostics, their calibration procedures, and the systematic testing of the components and the subsystems and its results will also be described and presented.