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How to lock or limit a free ballistic expansion of Energetic Particles?
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What could limit the free collisionless expansion? Dominant Scenario: -Instabilities / to create the “waves (as scatterers)”; -Feedback of growing fluctuations on particles due to the particles – waves interaction; -Non-Linear saturation of instability / build up of saturation spectrum;
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Add Fermi Acceleration
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Implementation of such scenario -Instability: Velocity Anisotropy (“Cyclotron Instability” of Alfven waves); -Feedback on particles: Quasilinear Theory of Particles/Cyclotron Waves Interaction; -Non-Linear saturation: Strong MHD / Alfven Waves/ Turbulence;
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Connection of Quasilinear Theory to KAM-Theory: From Planetary Resonances to Plasma
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x V
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V X ADD MORE WAVES
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Width of resonance Distance between resonances vs.
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much less than This limit corresponds to KAM (Kolmogoroff- Arnold-Mozer) case. KAM-Theorem : As applied to our case of Charged Particle – Wave Packet Interaction – “Particle preserves its orbit “
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greater than That means - overlapping of neighboring resonances Repercussions: -”collectivization” of particles between neighboring waves; -particles moving from one resonance to another – “random walk”? And if yes - what is Diffusion Coefficient ?(in velocity space)
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V X dV/dt =
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D= Repercussions: Quasilinear Theory, Plateau Formation, Beam + Plasma Instability Saturation etc.
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General Conclusions Kolmogoroff: Application of KAM theory to the Dynamics of Planetary System Plasma case: Application to the Dynamics of Charged Particles more applications: Waves-Particles interaction at Cyclotron Resonance Magnetic Surfaces Splitting? (Trieste, 1966) Advection in Fluids (+20 years)
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Quasilinear Diffusion. The simplified approach to such diffusion is equivalent to a truncation of quasilinear velocity space diffusion similar to tau-approximation form of collision integral in kinetic equation. Further simplifications: -Plasma pressure is much greater than Magnetic field pressure; -Bulk of plasma particles out of resonance with “waves” (even in strong turbulence definition); -CR particle density too small to produce competitive nonlinear effects by themselves and do not affect waves nonlinear saturation process.
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Add Fermi Acceleration
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Truncate Quasilinear Eqn
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Nonlinear Saturation Conjecture
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MHD + Expanding Cloud of Energetic Particles + “Return Current MHD Waves modified:
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Net effect of Instabilities Both types of Instability together:
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