Abstract: A resonator body 1 comprises a square-tube-shaped side wall 2 with upper and lower walls. A cavity 5 is formed in the resonator body. The side wall has a microwave supply opening 6. A wave guide 7 is connected to the microwave supply opening through an inductive window 13. The upper and lower walls have reaction tube attachment openings 3a, 4a. A reaction tube 8 is attached to the reaction tube attachment openings and extends vertically through the cavity and cross an axis of the wave guide. Square tubes 10a-10b made of non-magnetic metal meshes are arranged concentrically to the resonator body and in nested manner in the cavity at a distance from both the interior surface of the side wall and the reaction tube.

Abstract: A resonator body 1 comprises a square-tube-shaped side wall 2 with upper and lower walls. A cavity 5 is formed in the resonator body. The side wall has a microwave supply opening 6. A wave guide 7 is connected to the microwave supply opening through an inductive window 13. The upper and lower walls have reaction tube attachment openings 3a, 4a. A reaction tube 8 is attached to the reaction tube attachment openings and extends vertically through the cavity and cross an axis of the wave guide. Square tubes 10a-10b made of non-magnetic metal meshes are arranged concentrically to the resonator body and in nested manner in the cavity at a distance from both the interior surface of the side wall and the reaction tube.