G.G. Denisov - Corresponding Member of RAS, Head of Department, Institute of Applied Physics (Nizhni Novgorod); Professor, Nizhegorodskii State University n.a. N.I. Lobachevskii. E-mail: den@appl.sci-nnov.ru A.A. Bogdashov - Ph.D. (Phys.-Math.), Senior Research Scientist, Institute of Applied Physics (Nizhni Novgorod) I.G. Gachev - Ph.D. (Phys.-Math.), Senior Research Scientist, Institute of Applied Physics (Nizhni Novgorod) S.V. Mishakin - Ph.D. (Phys.-Math.), Senior Research Scientist, Institute of Applied Physics (Nizhni Novgorod) S.V. Samsonov - Dr.Sc. (Phys.-Math.), Senior Research Scientist, Institute of Applied Physics (Nizhni Novgorod) E.V. Sokolov - Ph.D. (Phys.-Math.), Senior Research Scientist, Institute of Applied Physics (Nizhni Novgorod); Director, JSC «Gikom» E.A. Soluyanova - Ph.D. (Phys.-Math.), Head of Department, JSC «Gikom» E.M. Tai - Ph.D. (Phys.-Math.), Director, Nizhegorodskii Department of JSC «Gikom»

The results of experimental investigation of two Ka-band gyrotron traveling-wave tubes (gyro-TWTs) with helically corrugated waveguides are presented. The first tube produces pulsed output power of 130-160 kW within the frequency range of 33.1-35.5 GHz and is capable of operating with a 10% duty factor. Reliability of its major components in the high average power operation regime (about 10 kW) was proven in a continuous-wave (CW) experiment. The second gyro-TWT amplifier delivered CW power of up to 7.7 kW with −3-dB bandwidth of 2.6 GHz and −1-dB bandwidth of 2.1 GHz. Effective implementation of single-stage depressed collectors (for the first time for gyro-TWTs) enabled the electron efficiencies as high as 36% for the pulsed tube and 33% for the CW tube to be achieved at operation at the second cyclotron harmonic.

 

1. Gaponov A.V. Vozbuzhdenie linii peredachi neprjamolinejjnym ehlektronnym puchkom // Izv. vuzov. Ser. Radiofizika. 1959. T. 2. № 3. S. 443-450.
2. Gaponov A.V., Petelin M.I., JUlpatov V.K. Inducirovannoe izluchenie vozbuzhdennykh klassicheskikh oscilljatorov i ego ispolzovanie v vysokochastotnojj ehlektronike // Izv. vuzov. Ser. Radiofizika. 1967.T. 10. № 9-10. S. 1415-1424.
3. Chu K.R., Chen H.Y., Hung C.L., Chang T.H., Barnett L.R. Ultrahigh gain gyrotron traveling wave amplifier // Phys. Rev. Lett. 1998.V. 81. № 21. R. 4760-4763.
4. Garven M., Calame J.P., Danly B.G., et al. A gyrotron-travelling-wave tube amplifier experiment with a ceramic loaded interaction region // IEEE Trans. Plasma Sci. 2002.V.30.№ 3. R. 885-893.
5. Pershing D.E., Nguyen K.T., Calame J.P., et al. A TE11 Ka-band Gyro-TWT amplifier with high-average power compatible distributed loss // IEEE Trans. Plasma Sci. 2004.V.32. № 3. R. 947-956.
6. Wang H., Li H., Luo Y., Yan R. Theoretical and experimental investigation of a Ka-band Gyro-TWT with lossy interaction structure // J. Infrared Millim. Terahertz Waves. 2011.V. 32. № 2. R. 172-185.
7. Wang E.F., Zeng X., Liu B.T., et al. Experimental study of 290 kW Ka-band gyrotron-traveling wave-tube // Proc. 13th IEEE Int. Vacuum Electronics Conference and 9th IEEE Int. Vacuum Electron Sources Conference (IVEC-IVESC 2012), Monterey, CA. USA. 2012. R. 215-216.
8. Blank M., Borchard P., Cauffman S., Felch F. W-band gyro-amplifiers at Haystack Ultra-Wide Satellite Imaging Radar // Digest of Joint 32nd Int. Conf. on Infrared and Millim. Waves and 15th Int. Conf. on THz Electronics. Cardiff, UK. 2007. R.364-366.
9. Denisov G.G., Bratman V.L., Phelps A.D.R., Samsonov S.V.Gyro-TWT with a Helical Operating Waveguide: New Possibilities to Enhance Efficiency and Frequency Bandwidth // IEEE Trans. on Plasma Science. 1998.V.26. № 3. R.508-518.
10. Bratman V.L., Denisov G.G., Samsonov S.V. i dr. Vysokoehffektivnye shirokopolosnye giro-LBV i giro-LOV so spiralno-gofrirovannymi volnovodami // Izv. vuzov. Ser. Radiofizika. 2007. T. 50. № 2. S. 104-116.
11. Samsonov S.V., Denisov G.G., Gachev I.G., et al. CW Ka-band kW-level Helical-Waveguide Gyro-TWT // IEEE Trans. on Electron Devices. 2012. V. 59. № 8. R. 2250-2255.