Effects of Output Peaking Capacitor on Underwater-Streamer Propagation

This paper describes the effects of an output peaking capacitor on the propagation of an underwater streamer. A pulsed-power modulator using a magnetic-pulse-compression circuit was employed to generate 20-30-kV pulses with 2-mus pulsewidth. A point-to-plane electrode setup with 2-cm gap in tap water was used. A copper line with 0.43-mm tip diameter was used as the discharge electrode, and an aluminum plate was set in water and connected to ground. Underwater-streamer propagation was visualized by an intensified-charge-coupled-device camera with a high-speed gate. An optional output peaking capacitor was connected in parallel to the electrodes to get pulses with different rise time and higher peak voltage and current. Thin and well-distributed channels were observed when the peaking capacitor was used. In contrast, the number of streamer channels was small, and each of them was thick and bright when the peaking capacitor was removed from the circuit. It is concluded that the peaking capacitor has a favorable effect on the generation and propagation of the underwater streamer.