A LASER TO MEASURE FRAGMENT VELOCITY AND MASS

WE ARE PROPOSING TO DEVELOP A LASER DIAGNOSTIC TOOL WHICH WILL MEASURE THE INITIAL (PEAK) VELOCITIES AND VOLUMES OF WARHEAD FRAGMENTS SIMULTANEOUSLY. THIS WILL BE ACCOMPLISHED BY TAKING TIME-SEQUENCED LASER SHADOW PHOTOGRAPHS OF THE WARHEAD SIMULTANEOUSLY ALONG THREE ORTHOGONAL AXIS SHORTLY AFTER DETONATION AND CALCULATING FRAGMENT VELOCITY AND VOLUME FROM THE CORRELATED IMAGES. THIS CAN BE ACCOMPLISHED USING A LASER SOURCE BECAUSE, UNLIKE IN THE CASE OF A FLASH X-RAY, BOTH THE PHOTON SOURCE AND THE CAMERA CAN BE LOCATED REMOTELY FROM THE WARHEAD AND THE LIGHT PULSES CONDUCTED TO AND FROM THE EXPLOSION SITE BY EXPENDABLE FIBER OPTICS OR MIRRORS WHICH CAN BE DESTROYED BY THE EXPLOSION. SINCE THE FRAGMENTS REACH THEIR PEAK VELOCITIES QUICKLY, ALL THE REQUIRED DATA CAN BE ACQUIRED ON THE IMMEDIATE VICINITY OF THE WARHEAD PROVIDING THE LASER CAN PENETRATE THE SHOCKED AIR AND DETONATION PRODUCTS THAT STILL SURROUND THE FRAGMENTS. THE GOAL OF OUR PHASE I PROGRAM IS TO DEMONSTRATE EXPERIMENTALLY THAT A LASER WITH A WAVELENGTH AROUND A HALF UM CAN PRODUCE WELL RESOLVED SHADOW IMAGES OF THE FRAGMENTS WITHOUT BEING UNDULY ATTENUATED BY THE HOT COMPRESSED AIR AND EXPLOSION PRODUCTS THAT SURROUND THE METAL PARTS AT THE TIME OF INTEREST. WITH SUCCESSFUL EXPERIMENTAL RESULTS, THE FEASIBILITY OF THIS INNOVATIVE TECHNIQUE WILL HAVE BEEN DEMONSTRATED.