Abstract: This invention concerns a lens system, particularly for focusing electrons, with a cylindrical lens with pole shoes or electrodes, between which an aperture is located. This aperture has a slot-shaped cross section perpendicular to the optical axis of the lens. The cylindrical lens (4) is combined with a magnetic lens (1) with which a quadripole field can be produced. The lenses are arranged with little or no distance between them and their optical axes run parallel to one another. The quadripole lens (1) has a slot-shaped aperture (10) which is oriented parallel to the opening (9-11) of the cylindrical lens (4). The focusing plane of the quadripole lens (1), which comprises the optical axis (19), is oriented parallel to the longitudinal axes of the apertures (9-11) and its defocusing plane perpendicular to the longitudinal axes. The refractive power of the cylindrical lens (4) can be set at twice that of the quadripole lens (1).

Abstract: The invention relates to apparatus for generating an electron beam with an ptical waveguide, a light source which is coupled on one end of the optical waveguide, a coating for generated electrons which is applied to the other end of the optical waveguide as well as field-generating means in order to lower the electron work function of the coating so far that a photoemission current can be generated. According to the invention a metal carbide is used as the coating.

Abstract: The invention relates to a corpuscular beam device, such as an ion beam dce or an electron beam device, in which a primary corpuscular beam is focussed by means of an objective lens onto a sample. The secondary radiation emitted at the point of impact of the primary beam is accelerated onto the central electrode of the objective lens, this electrode being coated with scintillation material, and there produces light pulses which are converted by a light-sensitive detector into electrical signals and amplified.

Abstract: In a flat picture-reproducing device having a phosphor-coated faceplate (1) and a tray-shaped rear housing (2), a cathode formed by a periodic array of heating wires (7) is provided. This heating-wire array is followed by layers of focusing wires (8) and attracting wires (9) and by a perforated anode (5). A segmented counterelectrode (6) is located behind the heating wires (7).

Abstract: There is disclosed a scanning particle microscope in which the adverse influence of the Boersch effect is reduced. This is achieved by providing an elastrostatic retardation element in the particle optics unit to decelerate the particle from a first energy, at which the particles are generated, to a second energy which is less than half of the first energy.

Abstract: A beam generator in a scanning particle microscope reduces energetic Boersch effect on the probe diameter to improve resolution by enabling beam particles to traverse a first beam crossover point with low energy and subsequently reaccelerating the beam particles to high energies while traversing the microscope's electro-optical column for subsequent deceleration shortly before reaching a specimen. An extraction electrode is provided between a Wehnelt electrode and an anode at a positive potential relative to a cathode, wherein the positive potential of the extraction electrode is substantially less than a positive potential at the anode.