RELEASE LIMITATION

A Photon Doppler Velocimeter (PDV) was built for explosives research. The PDV is comprised of a 1550 nm continuous-wave single-mode fibre laser, an optical circulator, a photodetector and a GHz range capable oscilloscope. As a test, it was used to record the velocity history of the back surface of 5 mm thick steel plates driven by the detonation products of PE4 charges of mass 15- 60 g. A bare fibre tip, located 1- 4 mm away from the target was used as the optical probe. Time resolution of 7 ns was achieved. The free surface velocity effects were interpreted in terms of the elastic-plastic model of steel, Chapman-Jouguet pressure was evaluated, and Gurney equations were applied to describe the motion of the steel plate. The measurement limitations of the PDV system are determined, applications for explosives research are discussed, and the upgrade pathway is recommended