volume | PIER Journals

Abstract

A 40 A triode type magnetron injection gun for a 1 MW, 120 GHz gyrotron has been designed. The preliminary design has been obtained by using some trade-off equations. Computer simulation has been performed by using the commercially available code EGUN and the in-house developed code MIGANS. The operating voltages of the modulating anode and the accelerating anode are 60 kV and 80 kV, respectively. The operating mode of the gyrotron is TE_22,6 and it is operated in the fundamental harmonic. The electron beam with a low transverse velocity spread (δβ_⊥max = 3.3%) and velocity ratio, α = 1.38 at beam current = 40 A is obtained. The simulated results of the MIG obtained with the EGUN code have been validated with another trajectory code TRAK. The results obtained from both the codes are in good agreement. The sensitivity study has been carried out by changing the different gun parameters to decide the fabrication tolerance.

1. Thumm, M., "High power gyro-devices for plasma heating and other applications," Int. J. Infrared Millim. Waves, Vol. 26, 483-503, Apr. 2005.
doi:10.1007/s10762-005-4068-8

2. Dammertz, G., et al., "Development of multimegawatt gyrotrons for fusion plasma heating and current drive," IEEE Trans. Plasma Sci., Vol. 52, No. 25, 808-817, May 2005.

3. Thumm, M., "State-of-the-art of high power gyro-devices and free electron masers update 2006,", Scientific Report FZKA 7289, Forschungszentrum Karlsruhe, Karlsruhe, Germany, Feb. 2007.

4. Flyagin, V. A., A. V. Gaponov, I. Petelin, and V. K. Yulpatov, "The gyrotron," IEEE Trans. Microwave Theory Tech., Vol. 25, No. 6, 514-521, 1977.
doi:10.1109/TMTT.1977.1129149

5. Gyrotron Oscillators: Their Principles and Practice, Edgcombe, C. J., Ed., Taylor & Francis, London, 1993.

6. Kartikeyan, M. V., E. Borie, and M. Thumm, Gyrotrons High-Power Microwave and Millimeter Wave Technology, Springer, Germany, 2004.

7. Nusinovich, G. S., Introduction to the Physics of Gyrotrons, Johns Hopkins University Press, Maryland, USA, 2004.

8. Goldenberg, A. L. and M. I. Petelin, "The formation of helical electron beams in an adiabatic gun," Izv. VUzov. Radiofizika, Vol. 16, 141-149, 1973.

9. Krivosheev, P. V., V. K. Lygin, V. N. Manuilov, and S. E. Tsimring, "Numerical simulation models of forming systems of intense gyrotron helical electron beams," Int. J. of Infrared and millimeter Waves, Vol. 22, 1119-1146, 2001.
doi:10.1023/A:1015006230396

10. Tsimring, S. E., "Gyrotron electron beams: Velocity and energy spread and beam instabilities," Int. J. of Infrared and millimeter Waves, Vol. 22, 1433-1468, 2001.
doi:10.1023/A:1015034506088

11. Choi, E. M., C. Marchewka, I. Mastovsky, M. A. Shapiro, J. R. Sirigiri, and R. J. Temkin, "Megawatt power level 120 GHz gyrotrons for ITER start-up," Journal of Physics: Conference Series, Vol. 25, 1-7, 2005.
doi:10.1088/1742-6596/25/1/001

12. Baird, J. M. and W. Lawson, "Magnetron injection gun (MIG) design for gyrotron applications," Int. J. Electronics, Vol. 61, 953-967, 1986.
doi:10.1080/00207218608920932

13. Lawson, W., "MIG scaling," IEEE Trans. Plasma Science, Vol. 16, No. 2, 290-295, 1988.
doi:10.1109/27.3827

14. Udaybir, S., A. Bera, R. R. Rao, and A. K. Sinha, "Synthesized parameters of MIG for 200 kW, 42 GHz gyrotron," J. of Infrared, Millimeter, and Terahertz Waves, 1886-6906, Dec. 2009 [online].

15. Hermannsfeldt, W. B., EGUN, Stanford Linear Accelerator Center, Stanford University Report SLAC-226, 1979.

16. Bera, A., S. Udaybir, R. R. Rao, and A. K. Sinha, "Design of MIG for 42 GHz, 200kW Gyrotron," IEEE IVEC-2008, Monterey, USA, 2008.

17. Udaybir, S., A. Bera, N. Kumar, and A. K. Sinha, "Numerical simulation of MIG for 200 kW, 42 GHz gyrotron," Int. J. of Infrared and millimeter Waves, Jan. 2010 [online].

18. TRAK 6.0, Finite-element Charged-particle Optics, Albuquerque, New Mexico 87192, U.S.A..

19. Lygin, V. K., B. Piosczyk, G. Dammertz, A. N. Kuftin, and V. E. Zapevalov, "A diode electron gun for a 1MW 140 GHz gyrotron," Int. J. Electronics, Vol. 82, No. 2, 193-201, 1997.
doi:10.1080/002072197136192

20. Fliflet, A. W., A. J. Dudas, M. E. Read, and J. M. Baird, "Use of electrode synthesis technique to design MIG-type guns for high power gyrotrons," International Journal of Electronics, Vol. 53, No. 6, 743-754, 1982.
doi:10.1080/00207218208901565

21. Barroso, J. J., A. Montes, and C. A. B. Silva, "The use of a synthesis method in the design of gyrotron electron guns," International Journal of Electronics, Vol. 59, No. 1, 33-47, 1985.
doi:10.1080/00207218508920676

22. Dryden, V. W., "Exact solutions for space-charge flow in spherical coordinates with application to magnetron injection guns," Journal of Applied Physics, Vol. 33, 3118-3124, 1962.
doi:10.1063/1.1728578

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

24. Borie, E. and B. Jödicke, "Comments on the linear theory of the gyrotron," IEEE Trans. Plasma Sci., Vol. 16, 116-121, 1988.
doi:10.1109/27.3802

25. Drobot, A. T. and K. Kim, "Space charge effects on the equilibrium of guided electron flow with gyromotion," Int. J. Electronics, Vol. 51, 351, 1981.
doi:10.1080/00207218108901342

26. Ganguli, A. K. and K. R. Chu, "Limiting current in gyrotrons," Int. J. of Infrared and Millimeter Waves, Vol. 5, 103, 1984.
doi:10.1007/BF01014037

27. Piosczyk, B., "A novel 4.5-MW electron gun for a coaxial cavity gyrotron," IEEE Transactions on Electron Devices, Vol. 48, No. 12, 2001.
doi:10.1109/16.974732

Mr. Udaybir Singh

Mr. Nitin Kumar

Dr. Narendra Kumar

Dr. Sakshi Tandon

Dr. Hasina Khatun

Dr. L. P. Purohit

Dr. Ashok Kumar Sinha