Laser-propelled ram accelerator

The concept of 'laser-propelled ram accelerator (L-RAMAC)' is proposed. Theoretically it is capable of achieving a higher launch speed than that by a chemical ram accelerator because a higher specific energy can be input to the propellant gas. The laser beam is supplied through the muzzle, focused as an annulus behind the base of the projectile. The performance of L-RAMAC is analized based on generalized Rankine-Hugoniot relations, suggesting that a superorbital muzzle speed is achievable out of this device

Ram accelerator operations at acceleration level up to 6 x 104 g

Experiments were conducted using a 25-mm-bore ram accelerator. By varying the projectile mass and the mixture fill pressure, the projectile acceleration level was varied by a factor of three. The acceleration performance is evaluated based on a ballistic efficiency. Over a velocity range from 80% to 110% of Chapman-Jouguet detonation velocity, the ballistic efficiency was kept almost constant, and did not depend on the acceleration level