Development of Railgun Accelerator at ISAS

Abstract

This paper describes the current status of the development of electromagnetic launchers such as the railgun at ISAS. The railgun is the most improved accelerator of Electromagnetic Launchers (EML). EML offers a potential of accelerating projectile to much greater velocities than those may be achived with conventional powder guns or light gas guns. But there has been little progress in increasing the velocity of EMLs since the experiment by Rashleigh and Marshall. A few experiments have reported achieving velocities more than 6km/s.
We have achieved the velocities more than 6km/s by reducing plasma leakage which is one of factors limiting velocity. In this paper a 6km/s launch is reported, comparing with the results of two other shots considering from a point of view of plasma leakage, and the effect of entrainment of eroded material into the armature by rail ablation were discussed on the basis of simulated numerical calculations.