摘要 |
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. According to this invention, the focusing system is used with high performance traveling-wave tubes.
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