Continuously Frequency Tunable High Power Sub-THz Radiation Source—Gyrotron FU CW VI for 600 MHz DNP-NMR Spectroscopy
A high frequency gyrotron with a 15 T superconducting magnet named Gyrotron FU CW VI has achieved continuous frequency tuning through the relatively wide range of 1.5 GHz near 400 GHz. The operation is at the fundamental cyclotron resonance of the TE06 cavity mode with many higher order axial modes. The output power measured at the end of the circular waveguide system ranges from 10 to 50 watts at the low acceleration voltage of 12 kV for beam electrons. The beam current is also low. It is around 250 mA. This gyrotron is designed as a demountable radiation source for the 600 MHz DNP-NMR spectroscopy. The design and operation results of the gyrotron FU CW VI are presented.
KeywordGyrotron DNP-NMR Frequency tunable sub-THz High power radiation source
This work was achieved under collaboration between the Research Center for Development of Far Infrared Region, University of Fukui (FIR FU) and the Institute for Protein Research, Osaka University. It was supported partially by the fund for Development of Advanced Measurement Device (Sentan Project) from Japan Science and Technology Agency (JST) and the Special Fund for Education and Research from Ministry of Education, Culture, Sports, Science and Technology (MEXT) in Japan. The authors would like to express many thanks to Mr. Iwahara and Mr. Yamamoto for their assistances in the operation test.
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