Measurement of delay time from propellant ignition to projectile launch in two-stage light gas gun using electrothermal-chemical gun technology

The hypervelocity impact experiments on the ground are indispensable in order to develop the defense structure over the impact with space structure and space debris. Today Two-Stage Light Gas Gun (TSLGG) is one of the most powerful accelerators. In Kyushu Institute of Technology, projectile velocity of 7.94 km/s was attained by means of the TSLGG with hydrogen gas. However it is well known that relative impact velocity at the low earth orbit is up to 15km/s. This impact velocity cannot be attained by the current TSLGG because sound velocity of light gas is smaller than 10km/s. Then, we have started a project of counter impacts in order to raise impact velocity. We developed a new TSLGG in which the technology of Electrothermal-Chemical (ETC) gun is applied to the 1st stage of TSLGG. In this paper, we measured delay time of ETC-based TSLGG as well as time variation of current, discharge voltage and pressure. And we succeeded to reduce jitter of the delay time small than +/- 0. 1msec.