A head lamp for a vehicle is provided. Also provided is a second flow restricting orifice disposed between a pilot for actuating the flow control valve and the inlet of the motor. The bit line is connected to the semiconductor region through first contact plugs. The tubular electrode is arranged so that a center axis of the tubular electrode is closer to an axis of travel of ions upstream of the input side plate-like electrode than an axis of travel of ions downstream of the output side plate-like electrode.