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INTERNATIONAL ASTROPHYSICS FORUM 2011. Frontiers in Space Environment Research, Alpbach/June 20-24, 2011. Turbulent equilibrium, and superhalo solar wind electron distribution, and nonextensive entropy. Peter H. Yoon U. Maryland, College Park, USA. Outline. Tsallis entropy
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INTERNATIONAL ASTROPHYSICS FORUM 2011 Frontiers in Space Environment Research, Alpbach/June 20-24, 2011 Turbulent equilibrium, and superhalo solar wind electron distribution, and nonextensive entropy Peter H. Yoon U. Maryland, College Park, USA
Outline • Tsallis entropy • Solar wind electrons • Beam-plasma instability • Turbulent equilibrium • Conclusions
Part 1. TSALLIS ENTROPY
Boltzmann entropy • S = k log W • W: # of ways a single molecule in an ideal gas can be arranged. • What does this mean?
A Toy Example • Two colored balls:
A Toy Example • Two colored balls: • In how many ways can the balls be arranged?
A Toy Example • Two colored balls: • In how many ways can the balls be arranged? • Answer: 2 • S = k log 2
S(W) = k log W kB = 1.3806503 x 10–23 m2 kg s–2 K–1 • : # of ways one molecule can be arranged in an ideal gas. • [Ref. K. Huang, Statistical Mechanics]
SA = k log 2 SB = k log 2
SA = k log 2 SB = k log 2 SA+B = k log 4= k log 2 + k log 2 = SA + SB
Extensivity of Boltzmann Entropy S(W) = k log W S(W’) = k log W’ S(WW’) = k log WW’ = S(W) + S(W’)
Non-Extensive Entropy S(W) = k log W S(W’) = k log W’ S(WW’) ≠ S(W) + S(W’)
Non-Extensive Entropy q defines the degree of non-extensivity. q = 1 (Boltzmann limit)
Boltzmann vs Tsallis Entropy Continuum limit Discrete versions
Part 2 SOLAR WIND ELECTRONS
2007 January 9 Linghua Wang, Robert P. Lin, Chadi Salem
fe(v) Electron Velocity Distribution By Linghua Wang, Davin Larsen, Robert Lin
Gaussian vs Kappa Distribution [Kappa distribution: Olbert, Vasyliunas]
Kappa Model Energetic (superthermal) tail = ∞
Most probable states • Helmholtz free energy
Boltzmann vsKappaDistributions as thermodynamic equilibria [Leubner, 2004; Treumann et al., 2008; Livadiotis and McComas, 2009]
Maxwellian (Gaussian) vs Kappa Distribution • If one defines • k= 1/(1–q) then Tsallis distribution becomes kappa-like distribution (Vasyliunas, 1968),
fe(v) Electron Velocity Distribution By Linghua Wang, Davin Larsen, Robert Lin
Part 3 BEAM-PLASMA INSTABILITY AND LANGMUIR TURBULENCE
Exospheric model [Scudder & Olbert, 1979; Pierrard et al., 2009, …] Turbulence model [this talk]
Bump-on-tail instability • A. Vedenov, E. P. Velikhov, R. Z. Sagdeev, Nucl. Fusion 1, 82 (1961). • W. E. Drummond and D. Pines, Nucl. Fusion Suppl. 3, 1049 (1962).
Quasi-linear beam-plasma interaction Spontaneous drag (discrete particle effect) Velocity space diffusion Spontaneous emission (fluctuation-dissipation theorem) Induced emission (Landau damping/ Quasi-linear growth/damping rate)
Weak turbulence theory L. M. Gorbunov, V. V. Pustovalov, and V. P. Silin, Sov. Phys. JETP 20, 967 (1965) L. M. Al’tshul’ and V. I. Karpman, Sov Phys. JETP 20, 1043 (1965) L. M. Kovrizhnykh, Sov. Phys. JETP 21, 744 (1965) B. B. Kadomtsev, Plasma Turbulence (Academic Press, 1965) V. N. Tsytovich, Sov. Phys. USPEKHI 9, 805 (1967) V. N. Tsytovich, Nonlinear Effects in Plasma (Plenum Press, 1970) V. N. Tsytovich, Theory of Turbulent Plasma (Consultants Bureau, 1977) A. G. Sitenko, Fluctuations and Non-Linear Wave Interactions in Plasmas (Pergamon, 1982)
Equation for fe(v) Spontaneous drag (discrete particle effect) Velocity space diffusion
Equation for I(k) Spontaneous emission (fluctuation-dissipation theorem) Induced emission (Landau damping/ Quasi-linear growth/damping rate)
Equation for I(k) Linear wave-particle resonance
Spontaneous decay Induced decay
Spontaneous scattering Induced scattering (scattering off thermal ions)
Discrete-particle (collisional) effect ~ g = 1/(nlD3)
Weak turbulence theory [Muschietti & Dum, 1991; Ziebell et al., 2001; Kontar & Pecseli, 2002]
Long-time behavior of bump-on-tail Langmuir instability P. H. Yoon, T. Rhee, and C.-M. Ryu, Self-consistent generation of superthermal electrons by beam-plasma interaction, PRL 95, 215003 (2005).
Theory C.-M. Ryu, T. Rhee, T. Umeda, P. H. Yoon, and Y. Omura, Turbulent acceleration of superthermal electrons, Phys. Plasmas 14, 100701 (2007).
fe(v) Electron Velocity Distribution By Linghua Wang, Davin Larsen, Robert Lin
Part 4 TURBULENT EQUILIBRIUM
fe(v) Electron kinetic equation I(k) Langmuir wave kinetic equation
Steady-State Solution (Quasi-Equilibrium) Electron kinetic equation Steady-state solution [Hasegawa et al., 1985]
• Balance of spontaneous emission and induced emission: • Self-consistent kappa distribution but k is undetermined:
• To determine k one must also balance spontaneous and induced scattering (turbulent equilibrium): =0