RAIL LAUNCHERS TO REACH HYPERVELOCITY

In this paper we present a theoretical study of a 80 mm round bore rai lgun which allows us, by a current distribution along the projectile, to accelerate a long rod penetrator with a fineness ratio of 30 up to a muzzle velocity of 2500 m/s with an overall efficiency greater than 30 %. This study was started because an optimal impact velocity which allows a given depth of penetration to be reached with a minimum kinet ic energy exists for all the targets (homogeneous, composite, structur ed or reactive). Two years ago we showed that this impact velocity is always greater than 2300 m/s for a heavy alloy penetrator with L/D = 3 0. For these velocities the electromagnetic rail launchers may have ef ficiencies over 35 % when classical powder guns have efficiencies abou t 20 %.