Abstract: This invention refers to a traveling-wave tube with cylindrical evacuated sheath 3, which is surrounded by a permanent-magnet system including pole shoes 1 and magnet rings 2 inserted between the pole shoes, while pole shoes 1 inserted in evacuated sheath 3 and the parts of them that surround beam axis 7 are designed as small tubes 4. Every second pole shoe is coupled as an active pole shoe 1 to magnet ring 2, and pole shoes 5 that are inserted between are connected with evacuated sheath 3. This traveling-wave tube is capable of focusing with greater efficiency and at higher frequencies than existing systems. This invention also provides that active pole shoes 1, which are coupled to magnet rings 2, are made of magnetic metal and that at least front ends 8 of small tubes 4 are made of non-magnetic metal. In addition, pole shoes 5 inserted between are made of non-magnetic and their small tubes 6 of magnetic metal.

Abstract: A method for manufacturing a tubular part for travelling-wave tubes, which includes firmly placing a magnetically soft tube on a cylindrical body, cutting the magnetically soft tube into individual annular pole pieces having planar lateral surfaces throughout, inserting a ring of non-magnetic material between each two respective annular pole pieces, soldering the non-magnetic rings to the annular pole pieces, removing the cylindrical body after the soldering step, and inserting a magnet between each two respective annular pole pieces.

Abstract: An electron collector for an electron beam tube, in particular a high performance transit time tube, employs a hollow member for receiving the electrons, which hollow member is surrounded by a metallic cooling sleeve which is grounded during operation of the tube and which is electrically insulated therefrom for an operating potential which deviates from the ground potential. The collector is particularly characterized in that it comprises a highly heat resistant material with a low vapor pressure (melting point at least approximately 2,000.degree.C) and apart from an insulating attachment in the area of its electron beam entry opening extends by forming a vacuum space completely free standing into the cooling sleeve. The cooling sleeve is blackened at its inner surface facing the collector and is permeated during operation by a coolant supplied from a forced cooling system.