Abstract: A tooth-wound coil of a stator or of a stator segment of a dynamo-electric machine having two straight sections spaced apart from each other and running substantially parallel. Two 180° curves are located on the ends thereof, wherein the straight sections have an active part area, the axial extend of which is less than or equal to that of the straight section. The tooth-wound coil has a symmetrical extension plane running in the longitudinal direction. An insulation material is provided around the straight sections of the tooth-wound coil. The material effects groove isolation and/or phase isolation in the stator or stator segment.

Abstract: A diaphragm-type bass loudspeaker has a housing (10), the housing walls (13, 14, 15) of which enclose a volume (25) which is formed on the rear side of its diaphragm (3). In a surface area of the housing walls (13, 14, 15) which bounds the volume (25) there is an opening (23).

Abstract: A detector is disclosed which includes an elliptical hollow mirror and a tube having a reflecting inner surface for conducting the light emitted by a specimen under investigation in a scanning electron microscope. A vacuum window is seated at the outer end portion of the tube directly ahead of a receiver.

Abstract: A detector for back-scattered electrons includes a scintillator crystal and a light-conducting device for directing away the secondary radiation to a receiver. The light-conducting device is placed against the scintillator crystal in such a way that the secondary radiation is directed away symmetrically to two lines of symmetry. The two lines of symmetry are located in the plane of the scintillator crystal and are at right angles to one another. In this way, a uniform illumination of the scanned image is obtained.

Abstract: The invention is directed to a method of preventing cathode damage when switching on an electron gun having a field emission cathode assembly including a cathode, a first electrode and a ground electrode. During normal operation of the electron gun, an extraction voltage is applied across the cathode and the first electrode and an accelerating voltage is applied across the cathode and the ground electrode. A direct galvanic connection is established between the cathode and the first electrode prior to normal operation of the electron gun. During a burn-in period, only the accelerating voltage is applied. This accelerating voltage may include an overvoltage of up to twenty percent. Then the galvanic connection between the cathode and the first electrode is interrupted and the extraction voltage is applied. An arrangement for carrying out the invention is also disclosed.

Abstract: A corpuscular-beam apparatus including a specimen holder having at least two degrees of freedom of translation and at least one degree of freedom of rotation, and control means for correcting the translational coordinates of the specimen holder automatically when the specimen holder is rotated and retaining a predetermined specimen point in its position in the apparatus. The improvement of the invention comprises the control means comprising means for controlling the rotational movement of the specimen holder stepwise in angular increments, the angular increments being chosen small so that the translational movement of the specimen point for each angular increment may be considered linear.