The railgun experiments on head-on collision of different mass bodies in 10-15 km/s range

Abstract

Existing techniques allow the launch of solid imparters up to only about 10 km/s. A way of doubling the effective velocity for collision experiments is to use two accelerators to produce a head-on collision. However, light-gas guns and conventional EM launchers with pre-accelerators are not suitable for this mode of operation due to the difficulty of synchronizing the projectile motion when travelling through long bores (from a few meters to tens of meters). The compacted plasma armature railgun (RG) developed at the Ioffe Institute has a much shorter bore because it operates at a constant-along-the-barrel acceleration close to the maximum value allowed by the projectile strength or electrothermal explosion of rails. Acceleration of a typical 1 cm body reaches /spl sim/1-5 MGees, so that 7 km/s is achieved in 56 cm bore. The short acceleration length makes it possible to synchronize the motion in two counter-firing RGs. We have done experiments with two sets-ups, one using two RGs having identical square bores of 2 mm across and the other using an 8 mm square bore RG opposed to a 2 mm bore. Exploiting a rotating-mirror camera and a laser we have photographed collision processes at relative velocities of 4.9+5.1=10 km/s and 5.9+4.5=10.4 km/s, respectively. The potentials of this approach are far from being exhausted.