Induction of Long Gap Discharge by Water Jet

This paper presents the images of a long gap discharge induced by a water jet. Spherical metal balls of 5-cm diameter were used as high-voltage, ground, and guiding electrodes. The distance between the high-voltage electrode and the ground one was 50 cm, and the distance between the high-voltage electrode and the guiding one was set to 75 cm. A tap water of 50 Omega ldr m resistivity was jetted from behind the guiding electrode toward the high-voltage electrode. A lightning impulse voltage of 1/40 mus generated with an impulse generator was applied to the high-voltage electrode. The leader discharge developed from the tip of the water jet toward the high-voltage electrode. After the discharge bridged between the water jet and the high-voltage electrode, the discharge developed along the water jet.