A low cost, small bore light-gas gun facility

摘要

A new, 1.8 mm bore diameter, two-stage light-gas gun facility is described. The inexpensive to operate Small Particle Hypervelocity Impact Range (SPHIR) facility, located at the California Institute of Technology Graduate Aerospace Laboratories, is capable of producing launch speeds in the range of 2-3 km/s for launch package masses up to 25 mg and typical speeds of 5 - 7 km/s for launch package masses less than 6 mg with maximum speeds exceeding 10 km/s. The cost of expendables for a shot in this facility is less than $500 USD and several experiments may be conducted in a single day by a single researcher. Currently, the range is launching 22.7 mg, 1.8 mm steel spheres and 5 mg, L/D = 1 nylon cylinders. Target selection is flexible and current work involves a variety of polymer, birefringent and metallic materials. Extensive diagnostic instrumentation is in the process of being acquired and installed. Current operational diagnostic capabilities include high-speed photography (up to framing rates of 1 million frames per second), laser profilometry of tested targets, and real time measurements of the target deformation using the dynamic optical techniques of photoelasticity and caustics.