caa a22 4500 386367981 CHVBK 20180307111943.0 cr unu---uuuuu 161130e198906 xx s 000 0 eng 10.1017/S0022377800013970 doi S0022377800013970 pii (NATIONALLICENCE)cambridge-10.1017/S0022377800013970 Weakly relativistic nonlinear orbit dynamics for intense ordinary-mode propagation near electron cyclotron resonance [Elektronische Daten] The nonlinear orbit equations are investigated analytically and numerically for a constant-amplitude electromagnetic wave (ωs, ks) with ordinary-mode polarization propagating perpendicular to a uniform magnetic field B0 êz. Relativisitic electron dynamics are essential in determining the maximum orbit excursion when the incident wave frequency ωs is near the nth harmonic of the electron cyclotron frequency Ωc. Coupled nonlinear equations are obtained for the slow evolution of the amplitude A(т) and phase ø(t) of the perpendicular orbit when ωs ≈ nΩc. The dynamical equations are reduced to quadrature and simplified analytically. At exact resonance (ωs = nΩc), if relativistic effects are (incorrectly) neglected, the maximum orbit excursion Amax approaches the unacceptably large value determined from the first (non-zero) solution to Jn(ns Ωs Amax) = 0, which totally invalidates the non-relativistic approximation. (Here ns Ωs = cks/Ωc.) As a contrasting illustrative example, for n = 1, ωs = Ωc and moderate pump strength, weak relativistic effects limit the maximum orbit excursion to the approximate value , where єs = ns ωs (Vz/c) Vq/c 1, and Vq is the axial quiver velocity in the applied oscillatory field. Physically, relativistic effects produce a nonlinear frequency shift that dynamically ‘detunes' the particle motion from exact cyclotron resonance, thereby limiting amplitude growth. Copyright © Cambridge University Press 1989 Davidson Ronald C. Science Applications International Corporation, McLean, Virginia 22102, U.S.A. Yang Tser-Yuan Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, U.S.A. Aamodt Richard E. Lodestar Research Corporation, Boulder, Colorado 80302, U.S.A. Journal of Plasma Physics Cambridge University Press 41/3(1989-06), 405-426 0022-3778 41:3<405 1989 41 PLA https://doi.org/10.1017/S0022377800013970 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0022377800013970 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Davidson Ronald C. Science Applications International Corporation, McLean, Virginia 22102, U.S.A NATIONALLICENCE 700 1- Yang Tser-Yuan Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, U.S.A NATIONALLICENCE 700 1- Aamodt Richard E. Lodestar Research Corporation, Boulder, Colorado 80302, U.S.A NATIONALLICENCE 773 0- Journal of Plasma Physics Cambridge University Press 41/3(1989-06), 405-426 0022-3778 41:3<405 1989 41 PLA CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge