volume | PIER Journals

Abstract

The multimode beam wave interaction behavior in a tapered, cylindrical cavity RF interaction structure of a 42 GHz gyrotron operating in the TE₀₃ mode has been investigated through nonlinear analysis and PIC simulation. A technique for producing the annular gyrating electron beam in PIC simulation code CST Particle Studio has been described. An energy transfer phenomenon from electron beam to RF has been demonstrated. The performance of cavity has been monitored to ensure the device operation in the desired mode and frequency. In the PIC simulation, the effect of beam velocity spread on the power output has been discussed. Using multimode behaviour, the effect of presence of nearby modes on the cavity performance has been observed. The simulation results have been compared with the results obtained from self-consistent single-mode analysis and time-dependent multimode analysis. It has been found that output power is well above the desired 200 kW level for the designed 42 GHz gyrotron operating in TE₀₃ mode.

1. Edgcombe, C. J. (ed.), "Gyrotron Oscillators: Their Principles and Practice," Taylor and Francis Ltd., London, 1993. Google Scholar

2. Kartikeyan, M. V., E. Borie, and M. K. Thumm, "Gyrotrons High-Power Microwave and Millimeter Wave Technology," Springer, Germany, 2004. Google Scholar

3. Nusinovich, G. S., "Introduction to the Physics of Gyrotrons," Johns Hopkins University Press, Baltimore, 2004. Google Scholar

4. Thumm, M. K., "State-of-the-art of high power gyro-devices and free electron masers update 2009 ,", Scientific Reports FZKA 7467, Forschungszentrum Karlsruhe, Karlsruhe, Germany, 2010. Google Scholar

5. Eichmeier, J. A. and M. K. Thumm, "Vacuum Electronics - Components and Devices,", Springer, New York, 2008. Google Scholar

6. Kreischer, K. E., R. J. Temkin, H. R. Fetterman, and W. J. Mulligan, "Multimode oscillation and mode competition in high-frequency gyrotrons," IEEE Trans. Microwave Theory Tech., Vol. 32, 481-490, 1984.
doi:10.1109/TMTT.1984.1132711 Google Scholar

7. Nusinovich, G. S., "Review of the theory of mode interaction in gyrodevices," IEEE Trans. Plasma Science, Vol. 27, No. 2, 313-326, Jun. 1999.
doi:10.1109/27.772257 Google Scholar

8. Chu, K. R., "Theory of electron cyclotron maser interaction in a cavity at the harmonic frequencies," Phys. Fluids, Vol. 21, 2354-2364, 1978.
doi:10.1063/1.862188 Google Scholar

9. Liu, P. K. and E. Borie, "Mode competition and self-consistent simulation of a second harmonic gyrotron oscillator," Int. J. Infrared Millimeter Waves, Vol. 21, No. 6, 855-882, 2000.
doi:10.1023/A:1026437315884 Google Scholar

10. Kreischer, K. E. and R. J. Temkin, "Linear theory of an electron cyclotron maser operating at the fundamental," Int. J. Infrared Millimeter Waves, Vol. 1, No. 2, 195-223, Jun. 1980.
doi:10.1007/BF01007116 Google Scholar

11. Danly, B. G. and R. J. Temkin, "Generalized nonlinear harmonic gyrotron theory," Phys. Fluids, Vol. 29, 561-567, 1986.
doi:10.1063/1.865446 Google Scholar

12. Kartikeyan, M. V., A. Kumar, S. Kamakshi, P. K. Jain, S. Illy, E. Borie, B. Piosczyk, and M. K. Thumm, "RF behavior of a 200-kW CW gyrotron," IEEE Trans. Plasma Science, Vol. 36, No. 3, 631-636, Jun. 2008.
doi:10.1109/TPS.2008.923762 Google Scholar

13. Fliflet, A. W., M. E. Read, and K. R. Chu, "A self-consistent field theory for gyrotron oscillators: Application to a low Q gyromonotron," Int. J. Electron., Vol. 53, No. 6, 505-521, Dec. 1982.
doi:10.1080/00207218208901545 Google Scholar

14. Fliflet, A. W., R. C. Lee, S. H. Gold, W. M. Manheimer, and E. Ott, "Time-dependent multimode simulation of gyrotron oscillators," Phys. Rev. A, Vol. 43, No. 11, 6166-6176, Jun. 1991.
doi:10.1103/PhysRevA.43.6166 Google Scholar

15. Reddy, D. M., A. K. Sinha, and P. K. Jain, "Eigenmode and beam-wave interaction simulation for small orbit gyrotron using MAGIC," International Conference on Microwaves, Antenna, Propagation & Remote Sensing, ICMARS, Jodhpur, Feb. 2008. Google Scholar

16. Wu, H., R. L. Liou, and A. H. McCurdy, "PIC code simulation of pulsed radiation in a tapered closed-cavity gyrotron," IEEE Trans. Plasma Science, Vol. 24, No. 3, 606-612, Jun. 1996.
doi:10.1109/27.532943 Google Scholar

17. Reddy, S. U. M., V. B. Naidu, S. K. Datta, P. K. Jain, and L. Kumar, "PIC simulation of a gyrotron-traveling-wave tube amplifier ," IEEE International Vacuum Electronics Conference (IVEC), 319-320, 2010.
doi:10.1109/IVELEC.2010.5503420 Google Scholar

18. CST-Particle Studio, , User's Manual, Darmstadt, Germany, 2011.

19. , , MAGIC User's Manual: 2007 Version of Magic 3D, ATK Mission Research, Washington, 2007.

Dr. Ashutosh Singh

Dr. B. Ravi Chandra

Dr. Pradip Kumar Jain