Provided are a bit patterned medium having a super-track, a method of tracking a track of the bit patterned medium, a head appropriate for the bit patterned medium, and an information recordingreproducing apparatus including the bit patterned medium and the head. The plurality of first closed circuits each includes one of a plurality of first battery devices interconnected in series, one of a plurality of secondary windings magnetically connected with each other through the core, and one of a plurality of first switching devices. The section of the central bore receiving the sample fluid and the sheath fluid has a frustoconical shape that converges and terminates in a section of the central bore that has a square cross section. The neutralizing mechanism at least partially neutralizes the ion beams before they enter the plasma discharge region. The response is then transmitted from the base unit to the remote unit for display.