PURPOSE: To reduce thermal deformation and maintain high efficiency by forming vanes and strap rings with a specific nonmagnetic conducting material and providing film layers mainly made of copper on surfaces of the vanes and strap rings.
CONSTITUTION: Multiple square vanes 12 are radially arranged toward the inner peripheral wall in the radial direction on the inner face of an anode cylinder 11 to form a resonant cavity 13, an operating cavity 14 with the preset diameter is formed at the center, strap rings 15 and 16 are arranged on both ends of the vanes 12 to stably perform π-mode oscillation, and every other vanes 12 are connected together. The anode cylinder 11 is made of oxygen free copper, the vanes 12 and the strap rings 15 and 16 are made of molybdenum which has a thermal expansion coefficient smaller than that of oxygen free copper and is one of nonmagnetic conducting materials with heat resistance, and film layers 17 and 18 mainly made of copper are formed on the surfaces by electroless plating.
NOBUE TOMOTAKA
HIKINO TEI
