Each of a plurality of flash lamps forming a light source is a bar lamp having an elongated cylindrical shape. In particular, the device comprises an expandable member, an inner member and one or more stop elements. The shaft can further have at least one first hole toward the first end with the first hole extending radially from the channel to an external surface of the shaft. A rectification circuit rectifies the AC component of this current. The width L1 of the recording track is smaller than a bottom read width BRW of the read and write elements, and the width L2 of the wide land track is larger than the bottom read width BRW of the read and write elements.