In a method and device for positioning the level of a slice during the generation of a slice exposure of an examination subject with an x-ray examination device, a reference image of the exterior of the examination subject is recorded by a camera on a line of sight proceeding transverse to the direction of examination. A supply passage and a return passage provide a fuel flow circuit for the fuel delivery system, the high pressure chamber being defined in part by a camshaft-driven plunger. In certain embodiments, the array of pixels is divided into a plurality of pixel groups. The cell capacitors of more than one of the plurality of unit cells are provided in a trench. A module contains both the shift command device and a mode selection device for selecting between the automatic and manual modes. Said fiber portion is coated with a material retained within a confined space and adapted to exert pressure on said Bragg grating to compress said portion of fiber radially and to stretch it longitudinally.