Simultaneous Photonic Doppler Velocimetry and Dual Axis Framing Technique

Flyer plates, accelerated by the electrical explosion of a metallic bridge, have historically primarily been characterised using velocity interferometery methods such as VISAR and Photonic Doppler Velocimetry (PDV). With the advent of high-fidelity three-dimensional magnetohydronamical codes such as ALEGRA and ALE-MHD, there is a requirement for the characterisation of spatially-resolved phenomena such as bridge burst, flyer formation and flyer break-up. Multiple high-speed cameras were integrated with PDV, to provide both flyer plate velocity and othogonal views of the flyer plate. Optically-upshifted PDV was used, and flyer plate velocities in excess of 4 km.s-1 were measured. Laser illumination enabled imaging with exposures as short as 5 ns to be obtained, effectively freezing the motion of the flyer plate. The experimental technique is described, and example data obtained is presented.