volume | PIER Journals

Abstract

This paper is devoted to the study of beam-wave interaction behavior of a 35 GHz photonic band gap cavity (PBGC) gyrotron operating in a higher order TE₃₄₁ mode. For the present gyrotron, PBGC is used instead of conventional tapered cylindrical cavity due to its promising feature of the mode selectivity. In order to observe the beam-wave interaction behavior, multimode theory has been used for the PBG cavity operating at the fundamental harmonic mode. Multimode theory provides the performance of a gyrotron in the presence of all competing modes. Results obtained from the analysis have been validated using a commercially available 3D PIC code. The energy and phase variations of electrons demonstrate the bunching mechanism as well as energy transfer phenomena. RF power output obtained from the analysis as well as PIC simulation is compared and is found in close agreement within 12%. More than 45 kW of stable RF power output is achieved in TE₃₄₁ mode with ~17% efficiency. The existence of competing modes has been considerably reduced, and the single mode operation of PBGC gyrotron has been achieved.

1. Kartikeyan, M. V., E. Borie, and M. K. Thumm, Gyrotrons: High Power Microwave and Millimeter Wave Technology, Springer, Germany, 2004.

2. Rzesnicki, T., B. Piosczyk, S. Kern, S. Illy, J. Jianbo, A. Samartsev, A. Schlaich, and M. Thumm, "2.2-MW record power of the 170-GHz European preprototype coaxial-cavity Gyrotron for ITER," IEEE Transactions on Plasma Science, Vol. 38, No. 6, 1141-1149, 2010.
doi:10.1109/TPS.2010.2040842 Google Scholar

3. Thumm, M., "State-of-the-art of high power gyro-devices and free electron masers, update 2011,", Forschungszentrum Karlsruhe, Germany, Scientific Reports FZKA 7467, 2012. Google Scholar

4. Hornstein, M. K., V. S. Bajaj, R. G. Griffin, and R. J. Temkin, "Continuous wave operation of a 460-GHz second harmonic gyrotron oscillator," IEEE Trans. Plasma Science, Vol. 34, 524-533, 2006.
doi:10.1109/TPS.2006.875769 Google Scholar

5. 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

6. 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, 855882, 2000. Google Scholar

7. Sirigiri, J. R., K. E. Kreischer, J. Macuhzak, I. Mastovsky, M. A. Shapiro, and R. J. Temkin, "Photonic band gap resonator Gyrotron," Phys. Rev. Lett., Vol. 86, 5628-5631, 2001.
doi:10.1103/PhysRevLett.86.5628 Google Scholar

8. Jang, K.-H., S.-G. Jeon, J.-I. Kim, J.-H. Won, J.-K. So, S.-H. Bak, A. Srivastava, S.-S. Jung, and G.-S. Park, "High order mode oscillation in a terahertz photonic-band-gap multibeam reflex klystron," Appl. Phys. Lett., Vol. 93, 211104, 2008.
doi:10.1063/1.3037026 Google Scholar

9. Liu, G., X. Chen, and C. Tang, "Design of a second cyclotron harmonic gyrotron oscillator with photonic band-gap cavity," J. Phys. D: Appl. Phys., Vol. 44, 295102-7, 2011. Google Scholar

10. Smirnova, E. I., A. S. Kesar, I. Mastovsky, M. A. Shapiro, and R. J. Temkin, "Demonstration of a 17-GHz, high-gradient accelerator with a photonic-band-gap structure," Phys. Review Lett., Vol. 95, 074801, 2005.
doi:10.1103/PhysRevLett.95.074801 Google Scholar

11. Gao, X., Z. Yang, Y. Xu, L. Qi, D. Li, Z. Shi, F. Lan, and Z. Liang, "Dispersion characteristic of a slow wave structure with metal photonic band gap cells," Nuclear Instruments and Methods in Physics Research A, Vol. 592, 292-296, 2008.
doi:10.1016/j.nima.2008.04.059 Google Scholar

12. Nanni, E. A., M. A. Shapiro, and R. J. Temkin, "A 250GHz photonic band gap gyrotron traveling wave amplifier," IEEE Thirteenth International Vacuum Electronics Conference (IVEC), 413-414, Monterey, CA, 2012. Google Scholar

13. Singh, A. and P. K. Jain, "Eigenmode analysis of metal photonic band gap cavity for Gyrotron operating in higher order mode," PIERS Proceedings, 1734-1738, Kuala Lumpur, Malaysia, Mar. 27-30, 2012. 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. Danly, B. G. and R. J. Temkin, "Generalized nonlinear harmonic gyrotron theory," Physics of Fluids, Vol. 29, 561-567, 1986.
doi:10.1063/1.865446 Google Scholar

Dr. Ashutosh Singh

Dr. Pradip Kumar Jain