Measurements at the ISL-EMA 1 railgun facility

The instrumentation of a 500 kJ, 15 mm-bore-diameter railgun and the power switching are described in detail. Emphasis is on electrooptical measurement techniques. The results presented include electrical measurements on the switching circuit, breech and muzzle voltages, and projectile position. In addition, material problems concerning rail erosion with plasma-driven projectiles are discussed. After ten shots with peak currents up to 600 kA, rails and insulators were fully operational. The rail material loss has been tolerable. The surface roughness increased remarkably, due to the formation of a porous, heterogeneous, nearly insulating surface layer of variable thickness.<
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