| 摘要 |
834,958. Travelling wave tubes. ENGLISH ELECTRIC VALVE CO. Ltd. Dec. 11, 1958 [March 12, 1958], No. 7938/58. Class 39(1). A uniform spatial magnetic field is established in the region of the cathode, and an alternating spatial magnetic field is set up in the wave tube by means of permanent magnets 5, 6. . . (n-3), (n-2), Fig. 2. The magnets are arranged alternately so that the annular members 11 are uni-polar; they are shaped in such a manner as to produce magnet fields in delay winding space 2 contain delay helix 3 in alternate senses and alternatively relatively strong and weak. The diameters of the projections 14 on the members 11 slowly decrease to the diameter of projections 17 until the members assume the form of the members P in which region the field in the tube is of constant strength by alternating direction. The purpose of the variable positioning of the projections 14 is to compensate for the leakage field due to the field in the region of the electron gun. |
