Abstract: The invention relates to a tunable magnetron comprising a rotatable tuning element (10) projecting into a ring shaped interaction space between coaxially arranged cathode and anode systems. The tuning element (10) is driven by an electric motor (11) and produces upon rotation a periodic variation of the tuning. The tuning element (10) is situated within the evacuated space of the magnetron and the motor (11) in situated outside said space. The drive torque of the motor is then transferred to the tuning element via a coupling (12) having two active parts situated one on each side of the evacuated envelope (17) of the magnetron. Such a coupling can only transfer a limited torque. According to the invention the magnetron comprises means for limiting the torque which can be transferred to the coupling (12), both upon starting and stopping, for example a torque limiter (21-26) between the motor (11) and the coupling (12), whereby the start and stop procedures can be performed with optimum torque.

Abstract: The invention relates to a tunable magnetron having coaxial cathode and anode systems (13 and 11, 12) which define therebetween an annular, evacuated interaction space (18) and a rotatable tuning body (20, 24) supported by two ball bearings (21, 22). The tuning body (20, 24) with its bearings (21, 22) is situated in an evacuated space (25) communicating with the interaction space (18). A magnetic circuit having two pole shoes (16, 17), situated one on each side of the interaction space for producing an axial magnetic field through the interaction space (18), is closed through the rolling bearing (21) situated closest to the interaction space. In order to prevent magnetic interaction forces between the rolling bodies from influencing the rotation in the case of continuous operation, in particular if the bearings have no retainer ring, at least the rolling bodies in the bearing (21) situated closest to the interaction space (18) are made of non-magnetic material, e.g.

Abstract: A bearing arrangement in a tunable magnetron, in which a sleeve-shaped body (12) is journalled on a central column (10) by means of two bearings (14, 15). The distance between the inner rings (18, 19) and outer rings (22, 23) of the bearings is determined by distance means (20, 21) which generally can be sleeve-shaped. According to the invention, at least one distance means, suitably both distance means, is temperature compensated by being composed of an odd number of partial elements (30-32; 37-39). The elements all extend in the longitudinal direction of the distance means, and each distance means includes two end elements (30, 32; 37, 39) which bear against the respective bearing part (18, 19; 22, 23) and an intermediate element (31; 38). The elements in each distance means are in such force-transmitting connection with each other that, with temperature variations, two adjacent elements impart to the distance means length variations in opposite direction.

Abstract: For the inspection of a reactor vessel (1) there is used a carriage (4) provided with wheels (15) to enable the carriage to be driven around a reactor opening (2). The carriage supports a mast (36), which is provided with inspection equipment (38) which can be driven along the mast. Known apparatus of this kind block the reactor opening, thereby to prevent other work from being carried out during an inspection period, for example such work as the change of fuel elements. According to the invention, the carriage with mast and inspection equipment are so formed that a geometric projection thereof onto a plane extending perpendicularly to the geometric axis of the cylindrical reactor vessel lies within a sector of less than 180.degree., with the exception of an area outside the geometric projection of the reactor hearth onto the same plane.

Abstract: A device for measuring the radiation from an object by means of an optical system. The optical system comprises scanning devices for horizontal and vertical scanning with refracting rotating prisms. At least one radiation reference source is arranged in the optical system along the path of radiation from the scanned object so that the radiation source can be scanned by the rotating prisms at intervals which are not coincident with the interval when the object is scanned.