High velocity electrothermal mass launchers

The authors discuss a new type of electrothermal mass launcher that is calculated to be capable of efficiently propellung projectiles to velocities in excess of 15 km/s. The launcher can be scaled up in size to launch heavy projectiles from a few grams to several tons. The gun uses a low atomic weight high pressure plasma with a temperature in its core region of several eV as the working fluid to propel projectiles by thermal expansion to a velocity about equal to the plasma sound speed. In these plasmas, the sound speed can be made to be extremely high (e.g. 20 km/s for polyethylene at 5 eV). The plasma is heated ohmically by axial currents or azimuthal currents inductively generated in the plasma