A sputtering target includes an outer target tube, an inner support tube of rectangular cross-sectional shape supporting a magnet carrier extending along substantially the entire length of the inner support tube; and a water cooling circuit including at least one passageway within said inner support tube with an inlet at one end thereof adapted to receive cooling water from an external source, at least one outlet aperture at an opposite end thereof opening to a chamber radially between the inner support tube and the outer target tube; and at least one cooling water outlet at the one end of the inner support tube.