Development of railgun accelerator at NCLI

Railgun experiments have been made at National Chemical Laboratory for Industry (NCLI). Two types of railguns having 30 mm square bore and round bore of 14 mm in diameter were made. A pulse transformer was employed in a capacitor bank energy source system in order to increase a efficiency of acceleration. The performance of the system was examined. A projectile position detector using a continuous X-ray beam was developed and employed together with a X-ray shadowgraph apparatus to determine the precise positions of acceralated projectiles. This diagnostic system including ordinary electromagnetic and optical probes for plasma have enabled us to obtain the relative position of the projectile and the plasma armature experimentally.