volume | PIER Journals

Abstract

In order to improve the efficiency of the quasi-optical mode converter, two methods to design mirror systems for a 170 GHz gyrotron operating in TE_32,9 mode are presented in this paper. The first method is to use Katsenelenbaum-Semenov Algorithm (KSA) to design the structure of the mirror. The second method to design the mirror system depends on the phase difference on the mirrors, so we name it PD method. The mirror system consists of three mirrors, and the mirror center position and mirror size are the same for both methods. For the first method, the scalar and vector correlation coefficients obtained at the window are 99.45% and 98.12%, respectively, and the mirror system has been designed with a transmission efficiency of 97.25%. The scalar and vector correlation coefficients and mirror system transmission efficiency are 99.73%, 98.85%, and 97.67% respectively for the second method. Simulation results of the two methods are compared and analyzed, which provide a reference for the design of gyrotron quasi-optical mode converter mirror system.

1. Tax, D. S., et al. "Experimental results on a 1.5 MW, 110 GHz gyrotron with a smooth mirror mode converter," J. Infr. Millim. Terahertz Waves, Vol. 32, No. 3, 358-370, 2011.
doi:10.1007/s10762-010-9720-2 Google Scholar

2. Zapevalov, V. E. and M. A. Moiseev, "Influence of aftercavity interaction on gyrotron efficiency," Radiophysics and Quantum Electronics, Vol. 47, 520-527, 2004.
doi:10.1023/B:RAQE.0000047243.18212.1d Google Scholar

3. Choi, E. M., M. A. Shapiro, J. R. Sirigiri, and R. J. Temkin, "Experimental observation of the effect of aftercavity interaction in a depressed collector gyrotron oscillator," Physics of Plasmas, Vol. 14, 093302, 2007.
doi:10.1063/1.2776911 Google Scholar

4. Jin, J., M. Thumm, G. Gantenbein, and J. Jelonnek, "A numerical synthesis method for hybrid-type high-power gyrotron launchers," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, No. 3, March 2017.
doi:10.1109/TMTT.2016.2630060 Google Scholar

5. Wang, W., T. Song, H. Shen, S. Deng, D. Liu, and S. Liu, "Quasi-optical mode converter for a 0.42 THz TE_17,4 mode pulsed gyrotron oscillator," IEEE Transactions on Electron Devices, Vol. 99, 1-5, 2017. Google Scholar

6. Jin, J., G. Gantenbein, J. Jelonnek, M. Thumm, and T. Rzesnicki, "A new method for synthesis of beam-shaping mirrors for off-axis incident Gaussian beams," IEEE Transactions on Plasma Science, Vol. 42, No. 5, 1380-1384, May 2014.
doi:10.1109/TPS.2014.2310903 Google Scholar

7. Murphy, J. A., "Distortion of a simple Gaussian beam on reflection from off-axis ellipsoidal mirrors," International Journal of Infrared and Millimeter Waves, Vol. 8, No. 9, 1165-1187, 1987.
doi:10.1007/BF01010819 Google Scholar

8. Bogdashov, A. A., et al. "Mirror synthesis for gyrotron quasi-optical mode converters," International Journal of Infrared and Millimeter Waves, Vol. 16, No. 4, 735-744, 1995.
doi:10.1007/BF02066633 Google Scholar

9. Perkins, M. P. and R. J. Vernon, "Two-dimensional phase unwrapping to help characterize an electromagnetic beam for quasi-optical mode converter design," Appl. Opt., Vol. 47, No. 35, 6606-6614, 2008.
doi:10.1364/AO.47.006606 Google Scholar

10. Katsenelenbaum, B. Z. and V. V. Semenov, "Synthesis of phase correctors shaping a specified field," Radio Engineering Electronic Physics, Vol. 12, 223-231, IEEE Press, New York, NY, USA, 1967. Google Scholar

11. Jin, J. B., B. Piosczyk, M. Thunmm, T. Rzesnicki, and S. C. Zhang, "Quasi-optical mode converter/mirror system for a high-power coaxial cavity gyrotron," IEEE Transactions on Plasma Science, Vol. 34, No. 4, 1508-1515, August 2006.
doi:10.1109/TPS.2006.877627 Google Scholar

12. Bogdashov, A. A., A. V. Chirkov, G. G. Denisov, D. V. Vinogradov, A. N. Kuftin, V. I. Malygin, and V. E. Zapevalov, "Mirror synthesis for gyrotron quasi-optical mode converters," International Journal of Infrared and Millimeter Waves, Vol. 16, No. 4, 735-744, April 1995.
doi:10.1007/BF02066633 Google Scholar

13. Yang, X., M. K. Thumm, A. Arnold, E. Borie, G. Dammertz, et al. "Progress toward optimization of phase-correcting mirrors for a multifrequency I-MW gyrotron," IEEE Transactions on Plasma Science, Vol. 34, No. 3, 652-658, 2006.
doi:10.1109/TPS.2006.874848 Google Scholar

14. Jin, J., et al. "Design of phase correcting mirror system for coaxial-cavity ITER gyrotron," Vacuum Electronics Conference IEEE, 2010. Google Scholar

15. Liu, J., et al. "Design of adapted phase correcting mirrors for gyrotrons," Vacuum Electronics Conference IEEE, 2013. Google Scholar

16. Liu, J., et al. "Vector method for synthesis of adapted phase-correcting mirrors for gyrotron output couplers," IEEE Transactions on Plasma Science, Vol. 41, No. 9, 2489-2495, 2013.
doi:10.1109/TPS.2013.2276915 Google Scholar

17. Jin, J., et al. "High-efficiency quasi-optical mode converter for a 1-MW TE_32,9-mode gyrotron," IEEE Transactions on Plasma Science, Vol. 41, No. 10, 2748-2753, 2013.
doi:10.1109/TPS.2013.2276108 Google Scholar

18. Dhakad, R. K., G. S. Baghel, M. V. Kartikeyan, and M. K. Thumm, "Output system for a 170-GHz/1.5-MW continuous wave gyrotron operating in the TE_28,12 mode," IEEE Transactions on Plasma Science, Vol. 43, No. 1, 391-397, January 2015.
doi:10.1109/TPS.2014.2368254 Google Scholar

19. Jin, J., G. Gantenbein, J. Jelonnek, M. Thumm, S. Alberti, J.-P. Hogge, M. Silva, and T. Goodman, "Quasi-optical mode converter for 1MW dual frequency gyrotrons," 2017 Eighteenth International Vacuum Electronics Conference (IVEC), 1-2, 2017. Google Scholar

Dr. Guohui Zhao

Dr. Qianzhong Xue

Dr. Yong Wang

Dr. Xuewei Wang

Dr. Shan Zhang

Dr. Gaofeng Liu

Dr. Lianzheng Zhang