Photonic Doppler Velocimetry of mini flyers driven by electrically exploded foils

To optimize the performance of exploding foil initiators, the velocity histories of mini flyers driven by electrically exploded foils were obtained by Photonic Doppler Velocimetry (PDV). A electrically driven flyer device was designed, which could generate a mini flyer with Φ0.35 mm×25 μm size and the flyers in tests do not have any special treatment. Two shot flyers were tested by PDV diagnostics, and the velocity histories of mini flyer were obtained. The effective length is about 160 ns. The maximum velocities of two shots of flyers are 4520, 4330 m·s^-1 respectively, and the velocity difference is about 4%, which having a good consistency. The profiles of two velocities have an evident inflection point. Before the point, the velocities grow quickly and reach 75% of the final velocity in 60 ns (0.01 mm displacement). After the point, the velocities grow relatively slow and finish the rest 25% acceleration in 100 ns.