A plasma gun for forming and launching a high-density, high-velocity, supersonic magnetized plasmoid

The use of high-velocity (>50 km/s) imploding plasma liners in PJMIF permits the use of a dense initial target plasma with a very high $\beta(\gt10)$. Our approach to form a high- $\beta$ and high-temperature target plasma is by the head-on merging and stagnation of dense and high-velocity magnetized plasmoids, transforming the kinetic energy of the plasmoids into its thermal energy. Plasma guns for launching magnetized plasmoids (e.g. spheromaks) have been developed since the 1950’s for a variety of applications. The development thread that is most germane to the magnetized plasmoid gun we need for PJMIF is along the line of magnetized coaxial plasma gun (MCPG) developed for injecting CT into magnetic fusion configuration [1–4]. In this paper, we propose the design of a CT injector (named HiBG1) for launching compact-toroid-like plasmoids which have an order-of-magnitude higher densities and twice the masses at similar velocities (>100 km/s) in a compact package with an order of magnitude smaller in volume than have been done before. The key to the approach is the use of the STG1 coaxial plasma gun which is designed to launch plasma jets at the required velocities but at densities an order of magnitude higher than the state-of-the-art plasma gun for accelerating a plasma jet [5]. To the STG1 gun is added a coil to produce the bias field needed to magnetize the plasma jet. The design operation of the gun and analysis of the physical processes that lead to the formation and launch of the desired magnetized plasmoid will be presented.