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A novel numerical calculation method for electron guns

Published online by Cambridge University Press:  15 July 2014

Y.F. Kang*
Affiliation:
Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an, People's Republic of China
J. Zhao
Affiliation:
Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an, People's Republic of China
J.Y. Zhao
Affiliation:
Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an, People's Republic of China School of Science, Chang'an University, Xi'an, People's Republic of China
T.T. Tang
Affiliation:
Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an, People's Republic of China
*
Address correspondence and reprint requests to: Y. F. Kang, Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China. E-mail: [email protected]

Abstract

The problem of initial thermal velocity and the space charge effect of electron guns in numerical simulations have been investigated deeply. In general, the current software can meet the engineering requirements. However, the electron's initial thermal velocity and the space charge effect lack sufficient consideration. The above two factors significantly limit the performances of electron guns. Moreover, the parameters of electron guns are approximated based on a limited number of electron trajectories. Thus, the statistical distribution of the beam electron resulting from its initial thermal velocity is not considered adequately in present software. This paper introduces the equivalent meridional projected trajectory equation and the curvilinear axis evolution theory of the current density of toroidal electron sub-beam, and subsequently the current and charge density distributions in electron guns can be derived through iteration calculation. Based upon, the virtual crossover of an electron gun is determined by its current density distribution. As well as, a relevant numerical algorithm is developed and the related program is modified based on the popular commercial software SOURCE. Tungsten cathode guns, LaB6 cathode guns, field mission guns and Pierce guns are simulated respectively by examples. The calculations prove that the modified software is effective and practical.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2014 

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References

REFERENCES

Burdovitsin, V.A. & Oks, E.M. (2008). Fore-vacuum plasma-cathode electron sources. Laser Part. Beams 26, 619635.CrossRefGoogle Scholar
Culter, C.C. & Hines, M.E. (1955). Thermal velocity effects in electron guns. Proc. IRE 43, 307315.Google Scholar
Hawkes, P.W. & Kasper, E. (1989). Principles of Electron Optics. London: Academic.Google Scholar
Morrell, A.M., Law, H.B., Ramberg, E.G. & Herold, E.W. (1974). Color Television Picture Tubes. New York: Academic.Google Scholar
Munro, E. (1997). Computational techniques for design of charged particle optical systems. In Handbook of charged Particle Optics (Orloff, J., ed.), pp.174. Boca Raton: CRC Press.Google Scholar
Ozur, G.E., Proskurovsky, D.I. & Rotshtein, V.P. et al. (2003). Production and application of low-energy, high-current electron beams. Laser Particle Beams 21, 157174.CrossRefGoogle Scholar
Septier, A. (1983). Applied Charged Particle Optics. New York: Academic.Google Scholar
Stratton, J.A. (1941). Electromagnetic Theory. New York: McGraw-Hill.Google Scholar
Tang, T.T. & Kang, Y.F. (2005). A new approach for evaluating the current and charge density distributions in electron guns and beams. Optik 116, 185193.CrossRefGoogle Scholar
Tang, T.T. (1986). Introduction to Applied Charged Particles Optics (in Chinese). Xi'an: Xi'an Jiaotong University Press.Google Scholar
Tang, T.T. (1996). Advanced Optical Electronics (in Chinese). Beijing: Beijing Science-Technology University Press.Google Scholar
Tang, T.T. (1982). Second and third order aperture aberrations of uniform magnetic field spectrometers. Optik 62, 379399.Google Scholar
Villa, F. & Luccio, A. (1997). Test of a high-gradient low-emittance electron gun. Laser Particle Beams 15, 427447.CrossRefGoogle Scholar
Weber, C. (1967). Analogue and digital methods for investigating electron-optical systems. Philips Res. Rep. (Suppl.) 6, 195.Google Scholar
Zhu, X.Q. & Munro, E. (1989). A computer program for electron gun design using second-order finite elements. J. Vac. ScI. Technol. B 7, 18621869.CrossRefGoogle Scholar