Evaluation of a Novel Plasma Launcher Behavior Using Magneto Hydro Dynamic Modeling-Coupled Time Varying Electron Energy Distribution Function

An Electro Magnetic (EM) launcher can be used as an experimental tool to accelerate small-mass specimens up to 300 m/s to study impact phenomena. A plasma armature is employed to avoid the friction produced by a sliding metal armature and, in particular, to prevent high-Z impurities from entering the tokamak. High currents are used to achieve high accelerations, resulting in high plasma temperatures. For this purpose, 2-D and axisymmetric plasma models are widely used as these are less complicated and fairly available. The presented model solves the entire set of magneto hydro dynamic, including transport equations of mass, momentum, and energy along, with the vector potential form of Maxwell's equation-coupled time-varying electron energy distribution function for the novel EM launcher in axial symmetry domain. Radiation of the energy balance is calculated using the P-1 radiation method by dividing the electromagnetic spectrum into several gray bands. Simulations are performed using Comsol Multiphysics 4.2 software.

Nomenclature

Electrical conductivity.

thermal conductivity.

Mass density.

Viscosity.

Heat capacity.

Enthalpy.

Diffusion flux of air.

Local mass concentration coefficient of air.

Diffusion coefficient of air.

Axial velocity.

Radial velocity.

Azimuthal component of the magnetic field intensity.

Axial Lorentz force.

Radial Lorentz force.

Electrostatic potential.

Axial current density.

Radial current density.

Gravitational acceleration of free space.

Electronic charge of free space.

Electric field intensity of free space.

Permeability of free space.

Net emission coefficient.

Absorption coefficient.

Plank's function.

Incident radiation.

Armature mass.

Pellet mass.

Inertial drag.

Viscous drag.

Lorentz force.

Dimensionless drag coefficient.

The heat flux.

Cross section.

Rail erosion coefficient.

Electron density.

Electron rate expression.

Electron mobility.

Electron diffusivity.

Electron energy density.

Energy loss/gain due to inelastic collisions.

Electron energy mobility.

Electron energy diffusivity.

Electron energy.

Mole fraction of the target species for reaction .

Rate coefficient for reaction .

Total neutral number density.