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Download or read book Concepts for Increasing the Projectile Velocity of an Implosion Driven Launcher written by Myles Hildebrand and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The ability to soft-launch projectiles of considerable mass (~1 g) to velocities exceeding 10 km/s is of interest in a number of scientific fields, including orbital debris impact testing. While all current technologies are limited to 10 km/s for this range of masses, the implosion-driven launcher uses explosives to shock-compress helium, driving well-characterized projectiles in the mass range of 0.1 - 10 g to velocities exceeding 10 km/s. The design shows excellent scalability, reaching similar velocities across different projectile sizes. A "virtual piston" driven by the implosion of a thin-walled tube replaces the pump tube of a conventional two-stage light gas gun. While the basic single-stage launcher is capable of regularly exceeding 10 km/s, this study outlines various modifications that could enable higher velocities. Elementary concepts including pressure and material considerations to increase projectile velocity are initially investigated. Advanced concepts aimed at reducing the initial shock loading while providing subsequent compressions to maintain a high driving pressure are also investigated. Experiments are performed with down-bore Photonic Doppler Velocimetry. A 1550 nm laser collimator is pointed down the end of the launch tube and is used to continuously measure the velocity of the projectile. The effects of the various concepts are evaluated by comparing these continuous velocity histories. The projectile integrity and terminal velocity are also verified using a high-speed camera. Projectile integrity at ultra-high accelerations is considered by examining the possibility of spall fracture as well as Rayleigh-Taylor instability. The ablation of the launch tube wall due to extreme temperatures and pressures is also investigated with a parallel experimental series, providing direct quantification of mass loss. The ablation and its counter intuitive positive effect on projectile velocity are discussed." --