Magnetron

摘要

A magnetron comprising an anode portion (60) having an anode cylinder (6) and vanes (7), a cathode portion (50) having a coil-shaped filament (1), magnetic poles (9,10) disposed at the upper and lower ends of the filament, ringshaped permanent magnets (13,14) preferably made of a Sr ferrite magnet containing La-Co, an input portion (70) and an output portion (80). The diameter Æa of the inscribed circle at the ends of the vanes (7) constituting the anode portion (60) is optionally in the range of 7.5 to 8.5mm, and the outside diameter Æc of the coil-shaped filament (1) constituting the cathode portion (50) is preferably in the range of 3.4 to 3.6mm.