MAGNETRON

PURPOSE:To prevent cooling fins from touching magnets, reduce their temperature and greatly improve the outlet drift by attaching ends of the cooling fins inside a cut formed on the side surface of a york for a magnetic circuit. CONSTITUTION:The side surface of an under york 41 is provided with a cut 41a into which cooling fins 5 are fitted. As shown in Fig.2, a magnetron is assembled by attaching ends of the cooling fins 5 in the cut 41a. Since the cooling fins 5 are fitted in the cut 41a of the under york 41, the cooling fins 5 can be accurately positioned without relying on the accuracy of assembly. As a result, there is not possibility that the cooling fins 5 shift in the axial direction either by being clamped by a band 7 or by being thermally expanded during operation, thereby preventing the cooling fins 5 from touching magnets 1 and 2. Furthermore, the area of the cooling fins 5 increases by that of the cut 41a, thereby improving the cooling efficiency of the magnetron.