Kabushiki Kaisha Toshiba

Japan Atomic Energy Research Institute

Atsushi Kasugai

Keishi Sakamoto

Yoshika Mitsunaka

Tsuyoshi Kariya

Masaki Tsuneoka

In a substantially circular waveguide constituting a mode converter in a gyrotron tube, there is a region whose transverse inner surface shape changes to a non-true circular shape from a true circular shape in a range of 0 mm to 5 mm toward a radiation aperture from the incident side. Therefore, an undesirable cavity resonator which causes parasitic oscillation can be prevented from being formed in the vicinity of an inlet of the mode converter. Therefore, the parasitic oscillation of the mode converter can be suppressed, and a conversion efficiency of the converter can be enhanced, because of the effective length of the mode converter can be enhanced in the limited actual length.

Mode converter and gyrotron tube provided with mode converter for converting mode of millimeter waves

In the gyrotron apparatus of the present invention, the microwave absorbing unit is provided around the insulation cylinder located between the microwave reflecting transmitter and the collector so as to electrically insulate them from each other, and constituting a part of the vacuum chamber. With this structure, the leakage of an unnecessary microwave to the outside through the insulation cylinder, which may occur when the apparatus is operated with a reduced potential of the collector with regard to the transmitter, can be more surely suppressed.

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Ibaraki-ken, Japan

Atsushi Kasugai