Micrometeroid Impact Simulations Using a Railgun Electromagnetic Accelerator

A railgun electromagnetic (EM) accelerator was used to conduct a series of hypervelocity micrometeoroid impact simulations. The tests were designed to demonstrate that railguns can provide a repeatable means of accelerating particles between 10-4 and 10-7 g to hypervelocities within a high-vacuum flight chamber. Soda-lime glass beads were accelerated up to 11 km/s impacting into silicon, aluminum, quartz, and various proprietary targets. The railgun accelerators used were 1 m long, 12.7 mm wide, square-bore railguns. The inductance gradient for these guns was 0.32 μH/m. The conductors of the gun were made of molybdenum, and the insulating sidewalls were made of either 40% glass-filled polycarbonate or black granite. The power supply for the guns was two capacitor banks in parallel. Aluminum fuses [0.254 to 2.54 mm (1 to 10 mil) thick] with various size glass beads attached to them served as the conducting plasma on vaporization. The beads were entrained in the plasma as it formed, and were accelerated with the plasma down the gun. Gun and flight range diagnostics, along with experimental setups and results for several of the experiments, are presented