Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-10T20:59:33.517Z Has data issue: false hasContentIssue false

Development mechanism of cathode surface plasmas of high current pulsed electron beam sources for microwave irradiation generation

Published online by Cambridge University Press:  01 August 2012

Limin Li*
Affiliation:
College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, China
L. Chang
Affiliation:
College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, China
L. Zhang
Affiliation:
College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, China
J. Liu
Affiliation:
College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, China
G. Chen
Affiliation:
College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, China
J. Wen
Affiliation:
College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, China
*
Address correspondence and reprint request to: Limin Li. National University of Defense Technology, Changsha, 410073, China. E-mail: Liminlee@yahoo.cn

Abstract

This paper presents the development mechanism of surface plasmas of carbon-fiber-cathode electron beam source and its effects on the operation of a high-power microwave source, reflex triode vircator powered by about 400 kV, 9 kA, about 350 ns pulsed power accelerator. Based on the current and voltage characteristics of diodes using carbon fiber cathode, the axial expansion velocity is 1.2 cm/μs and the delay time of explosive emission is 2 ns. Further, the comparison of carbon fiber and stainless steel cathodes is made. It was found that the threshold electric field for carbon fiber cathode is about 25 kV/cm, and the delay time of explosive emission and threshold electric field for stainless steel cathode is, respectively, 4.5 ns and 40 kV/cm. The radial expansion velocity of individual emitting centers is estimated to be 1.2 cm/μs, equal to the axial expansion velocity, and this shows the cathode plasma spots spherically expand. In the optimal diode gap for microwave irradiation or at the average current density of 230 A/cm2 using carbon fiber cathode, the screening radius was 0.67 cm, the lifetime of cathode emitting centers was about 60 ns, the cathode plasma density was 5 × 1015 cm−3, and the Debye radius of cathode plasma was <3 × 10−5 cm−3. The self-quenching behavior of explosive emission centers occurs, due to the process of cathode surface material release and cooling. The generation and self-quenching of emitting centers, and screening effect of cathode plasmas determine the increase and decrease of cathode emitting area, which is independent of the current density and background pressure. The relation between the lifetime of virtual cathode and background pressure was discussed. It was found, both theoretically and experimentally, that a lower background pressure indicates a longer microwave pulse or a better microwave waveform. It was observed by comparison that the temporary behavior of cathode emitting area is similar to the development process of microwave pulse. The changes of emitting area affects the stability of beam current injected into the virtual cathode region, further leading to the fluctuation of microwave pulse of vircator.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Alyokhin, B.V., Dubinov, A.E., Shamro, O.A., Shibalko, K.V., Stepanov, N.V. & Vatrunin, V.E. (1994). Theoretical and experimental studies of virtual cathode microwave devices. IEEE Trans. Plasma Sci. 22, 945959.CrossRefGoogle Scholar
Barker, R.J., Booske, J.H., Luhmann, N.C. & Nusinovich, G.S. (2005). Modern Microwave and Millimeter-Wave Power Electronics. New York: IEEE/Wiley.CrossRefGoogle Scholar
Benford, J., Swegle, J.A. & Schamiloglu, E. (2007). High Power Microwaves. New York: Taylor and Francis.CrossRefGoogle Scholar
Biswas, D. (2009). A one-dimensional basic oscillator model of the vircator. Phys. Plasma 16, 063104.CrossRefGoogle Scholar
Booske, J.H. (2008). Plasma physics and related challenges of millimeter-wave-to-terahertz and high power microwave generation. Phys. Plasmas 15, 055502.CrossRefGoogle Scholar
Chang, C., Liu, G.Z., Fang, J.Y., Tang, C.X., Huang, H.J., Chen, C.H., Zhang, Q.Y., Liang, T.Z., Zhu, X.X. & Li, J.W. (2010). Field distribution, HPM multipactor, and plasma discharge on the periodic triangular surface. Laser Part. Beams 28, 185193.CrossRefGoogle Scholar
Davis, H.A., Bartsch, R.R., Kwan, T.J.T., Sherwood, E.G. & Stringfield, R.M. (1987). Gigawatt-level microwave bursts from a new type of virtual cathode oscillator. Phys. Rev. Lett. 59, 288.CrossRefGoogle ScholarPubMed
Davis, W.D. & Miller, H.C. (1969). Analysis of the electrode products emitted by dc arcs in vacuum ambient. J. Appl. Phys. 40, 22122221.CrossRefGoogle Scholar
Deutsch, C. & Didelez, J.-P. (2011). Inertial confinement fusion fast ignition with ultra-relativistic electron beams. Laser Part. Beams 29, 3944.CrossRefGoogle Scholar
Filatov, R.A., Hramov, A.E., Bliokh, Y.P., Koronovskii, A.A. & Felsteiner, J. (2009). Influence of background gas ionization on oscillations in a virtual cathode with a retarding potential. Phys. Plasmas 16, 033106.CrossRefGoogle Scholar
Gilburd, L., Efimov, S., Gefen, A.F., Gurovich, V.T., Bazalitski, G., Antonov, O. & Krasik, Y.E. (2012). Modified wire array underwater electrical explosion. Laser Part. Beams 30, 215224.CrossRefGoogle Scholar
He, J., Cao, Y., Zhang, J., Wang, T. & Ling, J. (2011). Design of a dual-frequency high-power microwave generator. Laser Part. Beams 29, 479485.CrossRefGoogle Scholar
Jiang, W. & Kristiansen, M. (2001). Theory of the virtual cathode oscillator. Phys. Plasmas 8, 3781–787.CrossRefGoogle Scholar
Kadish, A., Faehl, R.J. & Snell, C.M. (1986). Analysis and simulation of virtual cathode oscillations. Phys. Fluid 29, 4192.CrossRefGoogle Scholar
Kasperczuk, A., Pisarczyk, T., Chodukowski, T., Kalinowska, Z., Gus'kov, S.Y., Demchenko, N.N., Klir, D., Kravarik, J., Kubes, P., Rezac, K., Ullschmied, J., Krousky, E., Pfeifer, M., Rohlena, K., Skala, J. & Pisarczyk, P. (2012). Plastic plasma as a compressor of aluminum plasma at the PALS experiment. Laser Part. Beams 30, 17.CrossRefGoogle Scholar
Kovalchuk, B.M., Zherlitsyn, A.A. & Pedin, N.N. (2010). Plasma-filled diode in the electron accelerator on base of a pulsed linear transformer. Laser Part. Beams 28, 547552.CrossRefGoogle Scholar
Krasik, Y.E., Dunaevsky, A. & Felsteiner, J. (2001 a). Plasma sources for high-current electron beam generation. Phys. Plasmas 8, 24662472.CrossRefGoogle Scholar
Krasik, Y.E., Dunaevsky, A., Krokhmal, A., Felsteiner, J., Gunin, A.V., Pegel, I.V. & Korovin, S.D. (2001 b). Emission properties of different cathodes at E ≤ 105 V/cm. J. Appl. Phys. 89, 23792399.CrossRefGoogle Scholar
Krasik, Y.E., Yarmolich, D., Gleizer, J.Z., Vekselman, V., Hadas, Y., Gurovich, V. T. & Felsteiner, J. (2009). Pulsed plasma electron sources. Phys. Plasmas 16, 057103.CrossRefGoogle Scholar
Krasov, V.I., Krinberg, I.A., Paperny, V.L., Korobkin, Y.V., Romanov, I.V., Rupasov, A.A. & Shikanov, A.S. (2007). Ion acceleration in a high-current cathode plasma jet expanding in vacuum. Tech. Phys. Lett. 33, 941944.CrossRefGoogle Scholar
Kumar, R., Puri, R.R. & Biswas, D. (2004). On the relation between the frequency of oscillation of a virtual cathode and injected current in one-dimensional grounded drift space. Phys. Plasmas 11, 324.CrossRefGoogle Scholar
Li, L., Cheng, G., Zhang, L., Ji, X., Chang, L., Xu, Q., Liu, L., Wen, J., Li, C. & Wan, H. (2011). Role of the rise rate of beam current in the microwave radiation of vircator. J. Appl. Phys. 109, 074504.Google Scholar
Li, L., Liu, L., Cheng, G., Chang, L., Wan, H. & Wen, J. (2009 a). Electrical explosion process and amorphous structure of carbon fibers under high-density current pulse igniting intense electron-beam accelerator. Laser Part. Beams 27, 511520.CrossRefGoogle Scholar
Li, L., Liu, L., Cheng, G., Xu, Q., Ge, X. & Wen, J. (2009 b). Layer structure, plasma jet, and thermal dynamics of Cu target irradiated by relativistic pulsed electron beam. Laser Part. Beams 27, 497509.CrossRefGoogle Scholar
Li, L., Liu, L., Cheng, G., Xu, Q., Wan, H., Chang, L. & Wen, J. (2009 c). The dependence of vircator oscillation mode on cathode material. J. Appl. Phys. 105, 123301.CrossRefGoogle Scholar
Li, L., Liu, L., Wan, H., Zhang, J., Wen, J. & Liu, Y. (2009d). Plasma-induced evolution behavior of space-charge-limited current for multiple-needle cathodes. Plasma Sour. Sci. Technol. 18, 015011.CrossRefGoogle Scholar
Li, L., Liu, L. & Wen, J. (2007). Microstructure changes of cathodes after electron emission in high power diodes. J. Phys. D: Appl. Phys. 40, 53385343.CrossRefGoogle Scholar
Li, L., Liu, L., Wen, J. & Liu, Y. (2009 e). Effects of CsI coating of carbon fiber cathodes on the microwave emission from a triode virtual cathode oscillator. IEEE Trans. Plasma Sci. 37, 1522.CrossRefGoogle Scholar
Li, L.M., Liu, L., Xu, Q., Chen, G., Chang, L., Wan, H. & Wen, J. (2009 f). Relativistic electron beam source with uniform high-density emitters by pulsed power generators. Laser Part. Beams 27, 335344.CrossRefGoogle Scholar
Lin, X.X., Li, Y.T., Liu, B.C., Liu, F., Du, F., Wang, S.J., Chen, L.M., Zhang, L., Liu, X., Liu, X.L., Wang, Z.H., Ma, J.L., Lu, X., Dong, Q.L., Wang, W.M., Sheng, Z.M., Wei, Z.Y. & Zhang, J. (2012). Directional transport of fast electrons at the front target surface irradiated by intense femtosecond laser pulses with preformed plasma. Laser Part. Beams 30, 3943.CrossRefGoogle Scholar
Liu, J.-L., Zhang, H.-B., Fan, Y.-W., Hong, Z.-Q. & Feng, J.-H. (2012). Study of low impedance intense electron-beam accelerator based on magnetic core Tesla transformer. Laser Part. Beams 30, 299305.CrossRefGoogle Scholar
Malyshev, I.F. & Rybas, K.P. (1964). Dependence of virtual cathode oscillation on vacuum. Electron Appar. 2, 179.Google Scholar
Mesyats, A. (2000). Cathode Phenomena in a Vacuum Discharge: The Breakdown, the Spark and the Arc. Moscow: Nauka.Google Scholar
Mesyats, G.A. (2005). Plasma Phys. Control. Fusion 47, A109A151.CrossRefGoogle Scholar
Mesyats, G.A. & Proskurovsky, D.I. (1989). Pulsed electrical discharge in vacuum. Berlin: Springer.CrossRefGoogle Scholar
Miller, R.B. (1982). An Introduction to the Physics of Intense Charged Particle Beams. New York: Plenum.CrossRefGoogle Scholar
Parker, R.K., Anderson, R.E. & Duncan, C.V. (1974). Plasma-induced field emission and the characteristics of high-current relativistic electron flow. J. Appl. Phys. 45, 24632479.CrossRefGoogle Scholar
Peng, J.-C., Liu, G.-Z., Song, X.-X. & Su, J.-C. (2011). A high repetitive rate intense electron beam accelerator based on high coupling Tesla transformer. Laser Part. Beams 29, 5560.CrossRefGoogle Scholar
Roy, A., Menon, R., Mitra, S., Kumar, S., Sharma, V., Nagesh, K.V., Mittal, K.C. & Chakravarthy, D.P. (2009). Plasma expansion and fast gap closure in a high power electron beam diode. Phys. Plasma 16, 053103.CrossRefGoogle Scholar
Roy, A., Patel, A., Menon, R., Sharma, A., Chakravarthy, D.P. & Patil, D.S. (2011). Emission properties of explosive field emission cathodes. Phys. Plasma 18, 103108.CrossRefGoogle Scholar
Sakagami, H., Sunahara, A., Johzaki, T. & Nagatomo, H. (2012). Effects of long rarefied plasma on fast electron generation for FIREX-I targets. Laser Part. Beams 30, 103109.CrossRefGoogle Scholar
Saveliev, Y.M., Sibbett, W. & Parkes, D.M. (2003). Current conduction and plasma distribution on dielectric (velvet) explosive emission cathodes. J. Appl. Phys. 94, 74167421.CrossRefGoogle Scholar
Shiffler, D., Haworth, M., Cartwright, K., Umstattd, R., Ruebush, M., Heidger, S., Lacour, M., Golby, K., Sullivan, D., Duselis, P. & Luginsland, J. (2008). Review of cold cathode research at the Air Force Research Laboratory. IEEE Trans. Plasma Sci. 36, 718728.CrossRefGoogle Scholar
Ulrich, A. (2012). Light emission from particle beam induced plasma: An overview. Laser Part. Beams 30, 199205.CrossRefGoogle Scholar
Wu, J., Wang, L., Qiu, A., Han, J., Li, M., Lei, T., Cong, P., Qiu, M., Yang, H. & Lv, M. (2011). Experimental investigations of X-pinch backlighters on QiangGuang-1 generator. Laser Part. Beams 29, 155160.CrossRefGoogle Scholar
Yarmolich, D., Vekselman, V., Gurovich, V.T., Gleizer, J.Z., Felsteiner, J. & Krasik, Y.E. (2008). Micron-scale width multislot plasma cathode. Phys. Plasma 15, 123507.CrossRefGoogle Scholar
Zhang, Y., Liu, J., Wang, S., Fan, X., Zhang, H. & Feng, J. (2011). Effects of dielectric discontinuity on the dispersion characteristics of the tape helix slow-wave structure with two metal shields. Laser Part. Beams 29, 459469.CrossRefGoogle Scholar
Zhou, C.T., Cai, T.X., Zhang, W.Y. & He, X.T. (2012). Effect of plasma material on intense laser-driven beam electrons in solid foils. Laser Part. Beams 30, 111116.CrossRefGoogle Scholar