Electromagnetic launchers-the new concept

The dielectric body in a channel of electromagnetic launcher (EML) accelerates under action of pressure of plasma. There are severe enough basis to consider that in a channel of constant cross section the velocity of plasma flow can not surpass a velocity of sound in plasma. Accordingly, the maximum accessible velocity of throwing projectiles in EML is limited to a velocity of sound. The velocity of sound in plasma is determined by its composition and temperature. The plasma in a channel of EML is usually produced due to erosion of walls of the channel. Under typical conditions of EML operation the velocity of sound in plasma is 5-7 km/s that coincides with values of throwing velocity obtained experimentally. The increase of a velocity of throwing can be reached only at increase of the velocity of sound in plasma. The probable solutions permitting to raise the velocity of sound till 10-12 km/s are discussed. Probably, it is impossible to receive values of sound velocity above 15-20 km/s for the working conditions of EML, therefore the velocity of throwing at a level 12-15 km/s is limiting for EML. One of methods of increase of a sound velocity in EML is the using of the massive initiators from lithium and graphite. The results of experimental study of the EML characteristics with such initiators have been presented. It has been shown, that at usage of such initiators erosion of walls of a channel essentially decreases, and the high values of conversion of electromagnetic energy brought to a channel, in a kinetic energy of projectile (about 20 %) have been reached.