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Lower hybrid current drive in a tokamak for correlated passes through resonance

Part of: Focus on Fusion

Published online by Cambridge University Press:  10 June 2021

Peter J. Catto Open the ORCID record for Peter J. Catto [Opens in a new window]
Peter J. Catto*
Affiliation:
Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, USA
*
† Email address for correspondence: catto@psfc.mit.edu
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Abstract

Standard quasilinear descriptions are based on the constant magnetic field form of the quasilinear operator so improperly treat the trapped electron modifications associated with tokamak geometry. Moreover, successive poloidal transits of the Landau resonance during lower hybrid current drive in a tokamak are well correlated, and these geometrical details must be properly retained to account for the presence of trapped electrons that do not contribute to the driven current. The recently derived quasilinear operator in tokamak geometry accounts for these features and finds that the quasilinear diffusivity is proportional to a delta function with a transit or bounce averaged argument (rather than a local Landau resonance condition). The new quasilinear operator is combined with the Cordey (Nucl. Fusion, vol. 16, 1976, pp. 499–507) eigenfunctions to properly derive a rather simple and compact analytic expression for the trapped electron modifications to the driven lower hybrid current and the efficiency of the current drive.

Keywords

plasma confinementfusion plasmaplasma flows
Type
Research Article
Information
Journal of Plasma Physics , Volume 87 , Issue 3 , June 2021 , 905870309
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Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press

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References

Antonsen, T.M. & Chu, M.S. 1982 Radio frequency current generation by waves in toroidal geometry. Phys. Fluids 25, 1295–1296.CrossRefGoogle Scholar
Bonoli, P.T. 2014 Review of recent experimental and modeling progress in the lower hybrid range of frequencies at ITER relevant parameters. Phys. Plasmas 21, 061508.CrossRefGoogle Scholar
Catto, P.J. 2020 Collisional effects on resonant particles in quasilinear theory. J. Plasma Phys. 86, 815860302.CrossRefGoogle Scholar
Catto, P.J. & Tolman, E.A. 2021 Reimagining full wave quasilinear theory in a tokamak. J. Plasma Phys. 87, 905870215.CrossRefGoogle Scholar
Chiu, S.C., Chan, V.S., Harvey, R.W. & Porkolab, M. 1989 Theory of fast wave current drive for tokamak plasmas. Nucl. Fusion 29, 2175–2186.CrossRefGoogle Scholar
Cohen, R.H. 1987 Effect of trapped electrons on current drive. Phys. Fluids 30, 2442–2449.CrossRefGoogle Scholar
Cordey, J.G. 1976 Effects of particle trapping on the slowing-down of fast ions in a toroidal plasma. Nucl. Fusion 16, 499–507.CrossRefGoogle Scholar
Cordey, J.G., Edlington, T. & Start, D.F.H. 1982 A theory of currents induced by radio-frequency waves in toroidal plasmas. Plasma Phys. 24, 73–89.CrossRefGoogle Scholar
Ehst, D.A. & Karney, C.F.F. 1991 Approximate formula for radio-frequency current drive efficiency with magnetic trapping. Nucl. Fusion 31, 1933–1938.CrossRefGoogle Scholar
Fisch, N.J. 1978 Confining a tokamak plasma with rf-driven currents. Phys. Rev. Lett. 41, 873–876.CrossRefGoogle Scholar
Fisch, N.J. & Boozer, A.H. 1980 Creating an axisymmetric plasma resistivity with waves. Phys. Rev. Lett. 45, 720–722.CrossRefGoogle Scholar
Fisch, N.J. & Karney, C.F.F. 1981 Current generation with low-frequency waves. Phys. Fluids 24, 27–39.CrossRefGoogle Scholar
Giruzzi, G. 1987 Impact of electron trapping on rf current drive in tokamaks. Nucl. Fusion 27, 1934–1939.CrossRefGoogle Scholar
Helander, P., Geiger, J. & Maaßberg, H. 2011 On the bootstrap current in stellarators and tokamaks. Phys. Plasmas 18, 092505.CrossRefGoogle Scholar
Helander, P. & Sigmar, D.J. 2002 Collisional Transport in Magnetized Plasmas, pp. 191–195. Cambridge University Press.Google Scholar
Hinton, F.L. & Hazeltine, R.D. 1976 Theory of plasma transport in toroidal confinement systems. Rev. Mod. Phys. 48, 239–308.CrossRefGoogle Scholar
Hsu, C.T., Catto, P.J. & Sigmar, D.J. 1990 Neoclassical transport of isotropic fast ions. Phys. Plasmas B 2, 280–290.Google Scholar
Karney, C.F.F. & Fisch, N.J. 1979 Numerical studies of current generation by radio-frequency traveling waves. Phys. Fluids 22, 1817–1824.CrossRefGoogle Scholar
Karney, C.F.F. & Fisch, N.J. 1985 Efficiency of current drive by fast waves. Phys. Fluids 28, 116–126.CrossRefGoogle Scholar
Kennel, C.F. & Engelmann, F. 1966 Velocity space diffusion from weak plasma turbulence in a magnetic field. Phys. Fluids 9, 2377–2388.CrossRefGoogle Scholar
Parker, J.B. & Catto, P.J. 2012 Variational calculation of neoclassical ion heat flux and poloidal flow in the banana regime for axisymmetric magnetic geometry. Plasma Phys. Control. Fusion 54, 085011.CrossRefGoogle Scholar
Pusztai, I. & Catto, P.J. 2010 Neoclassical plateau regime transport in a tokamak pedestal.. Plasma Phys. Control. Fusion 52, 075016.CrossRefGoogle Scholar
Spitzer, L. & Härm, R. 1953 Transport phenomena in a completely ionized gas. Phys. Rev. 89, 977–981.CrossRefGoogle Scholar
Taguchi, M. 1983 The effect of trapped electron on the wave-induced current. J. Phys. Soc. Japan 52, 2035–2040.CrossRefGoogle Scholar
Xiao, Y., Catto, P.J. & Molvig, K. 2007 Collisional damping for ion temperature graient mode driven zonal flow. Phys. Plasmas 14, 032302.CrossRefGoogle Scholar
Yoshioka, K. & Antonsen, T.M. Jr. 1986 Neoclassical effects on rf current drive in tokamaks. Nucl. Fusion 26, 839–847.CrossRefGoogle Scholar