Characteristics of corona discharge from multi-pin electrodes

The GMR head in the tape recording is suffered from the corona discharge generated by tribo-electrification. In order to estimate the reliability of the head materials, the corona discharge using multi-pin electrodes was studied. The multi-pin electrodes were configured with maximum 15 pins. Each pin was distanced 5mm from neighbors and placed at 11mm over the Al plate. At negative voltage, the discharge started with isolated pulses. As the voltage increasing over -7kV, DC component appeared and increased. At positive voltage, the discharge was isolated pulses up to +10kV and DC component did not appeared. At 15-pins electrode, the period between the pulses was random and the peak values varied. Therefore, the corona discharges from the multi-pin electrodes occurred individually at each electrode. The mean current of 15-pins increased approximately five times at negative voltage and twenty times at positive voltage compared with that of single-pin.