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Parametric up-conversion of a trivelpiece–gould mode in a beam–plasma system

Published online by Cambridge University Press:  01 March 2004

D.N. GUPTA  and
A.K. SHARMA
D.N. GUPTA
Affiliation:
Department of Physics, University of Rajasthan, Jaipur, India
A.K. SHARMA
Affiliation:
Center for Energy Studies, Indian Institute of Technology, New Delhi, India
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Abstract

A large amplitude Trivelpiece–Gould (TG) mode, in a strongly magnetized beam–plasma system, parametrically couples to a beam space charge mode and a TG mode sideband. The density perturbation associated with the beam mode couples with the electron oscillatory velocity, due to the pump wave, to produce a nonlinear current, driving the sideband. The pump and the sideband waves exert a ponderomotive force on the electrons with a component parallel to the ambient magnetic field, driving the beam mode. For a pump wave having k0·v0b0/ω0 < 0, where ω0, k0 are the frequency and the wave number of the pump, and v0b0 is the beam velocity, the sideband is frequency upshifted. At low beam density (Compton regime) the growth rate of the parametric instability scales as two-thirds power of the pump amplitude, and one-third power of beam density. In the Raman regime, the growth rate scales as half power of beam density and linearly with pump amplitude. The background plasma has a destabilizing role on the instability.

Keywords

Beam–plasma systemParametric up-conversionTG mode
Type
Research Article
Information
Laser and Particle Beams , Volume 22 , Issue 1 , March 2004 , pp. 89 - 94
Copyright
2004 Cambridge University Press

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References

REFERENCES

Allen, G.R., Owens, D.K., Seiler, S.W., Yamada, M., Ikezi, H. & Porkolab, M. (1978). Parametric lower-hybrid instability driven by modulated electron-beam injection. Phys. Rev. Lett. 41, 1045–1048.CrossRefGoogle Scholar
Amatucci, W.E., Walker, D.N., Ganguli, G., Antoniades, J.A., Duncan, D., Bowles, J.H., Gavrishchaka, V. & Koepke, M.E. (1996). Plasma response to strongly sheared flow. Phys. Rev. Lett. 77, 1978–1981.CrossRefGoogle Scholar
Berger, R.L., Chen, L., Kaw, P.K. & Perkins, F.W. (1976). Lower hybrid parametric instabilities-nonuniform pump waves and tokamak applications. Phys, Fluids 20, 1864–1875.Google Scholar
Chang, J., Raether, M. & Tanaka, S. (1971). Experimental observation of wave-wave coupling in a beam-plasma system. Phys. Rev. Lett. 27, 1263–1266.CrossRefGoogle Scholar
Davydova, T.A., Lashkin, V.M, Shamrai, K.P. (1986). Effect of external rf field on instability of Trivelpiece-Gould waves in a plasma with an electron beam. Sov. J. Plasma Phys 12, 235–237.Google Scholar
Koepkr, M.E. (2002). Contributions of Q-machine experiments to understanding auroral particle acceleration processes. Phys. Plasmas 9, 2420–2427, and reference therein.Google Scholar
Krafft, C., Volokitin, A.S. & Fle, M. (2000). Nonlinear electron beam interaction with a whistler wave packet. Phys. Plasmas 7, 4423–4432.CrossRefGoogle Scholar
Liu, C.S., Tripathi, V.K., Chan, V.S. & Stefan, V. (1984). Density threshold for parametric instability of lower-hybrid waves in tokamaks. Phys. Fluids 27, 1709–1717.CrossRefGoogle Scholar
Maslennikov, D.I., Mikhailenko, V.S. & Stepanov, K.N. (2000). Decay instability of a lower hybrid wave. Plasma Physics Report 26, 139–146.CrossRefGoogle Scholar
Obiki, T., Itatani, R. & Otani, Y. (1968). Suppression of a two-stream interaction in a beam-plasma system by external ac electric fields. Phys. Rev. Lett. 20, 184–187.CrossRefGoogle Scholar
Porkolab, M. (1974). Theory of parametric instability near the lower-hybrid frequency. Phys. Fluids 17, 1432–1442.CrossRefGoogle Scholar
Porkolab, M., Bernabei, S., Hooke, W.M., Motley, R.W. & Nagashima, T. (1977). Observation of parametric instabilities in lower-hybrid radio frequency heating of tokamaks. Phys. Rev. Lett. 38, 230–233.CrossRefGoogle Scholar
Prabhuram, G. & Sharma, A.K. (1992). Second harmonic excitation of TG mode in a beam plasma system. J. Plasma Phys. 48, 3–12.CrossRefGoogle Scholar
Sakawa, Y., Joshi, C., Kaw, P.K., Chen, F.F., Jain, V.K. (1993). Excitation of the modified Simon–Hoh instability in an electron beam produced plasma. Phys. FluidsB5(6), 1681–1694.CrossRef
Seiler, S., Yamada, M. & Ikezi, H. (1976). Lower hybrid instability driven by a spiraling ion beam. Phys. Rev. Lett. 37, 700–703.CrossRefGoogle Scholar
Sharma, S.C., Srivastava, M.P., Sugawa, M. & Tripathi, V.K. (1998). Excitation of lower hybrid waves by a density-modulated electron beam in a plasma cylinder. Phys. Plasmas 5, 3161–3164.CrossRefGoogle Scholar
Taylor, R.J., Brown, M.L., Fried, B.D., Grote, H., Liberati, J.R., Morales, G.J., Pribyl, P., Darrow, D. & Ono, M. (1989). H-mode behavior induced by cross-field currents in a tokamak. Phys. Rev. Lett. 63, 2365–2368.CrossRefGoogle Scholar
Volokitin, A.S. & Krafft, C. (2001). Electron beam interaction with lower hybrid waves at Cherenkov and cyclotron resonances. Phys. Plasmas 8, 3748–3758.CrossRefGoogle Scholar
Wang, J.G., Suk, H. & Reiser, M. (1996). Experimental studies of space-charge waves and resistive-wall instability in space-charge-dominated electron beams. Fusion Engineering and Design 32–33, 141–148.CrossRefGoogle Scholar
Yatsui, K. & Imai, T. (1975). Plasma heating by lower-hybrid parametric instability pumped by an electron beam. Phys. Rev. Lett. 35, 1279–1282.CrossRefGoogle Scholar