Simulations of pitch angle scattering of relativistic electrons with MLT-dependent diffusion coefficients

2009 ◽  
Vol 114 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Yuri Y. Shprits ◽  
Lunjin Chen ◽  
Richard M. Thorne
Keyword(s):  
Diffusion Coefficients ◽  
Pitch Angle ◽  
Relativistic Electrons ◽  
Angle Scattering

scholarly journals Pitch Angle Scattering of Sub‐MeV Relativistic Electrons by Electromagnetic Ion Cyclotron Waves

2019 ◽  
Vol 124 (7) ◽  
pp. 5610-5626 ◽  
Author(s):  
R. E. Denton ◽  
L. Ofman ◽  
Y. Y. Shprits ◽  
J. Bortnik ◽  
R. M. Millan ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Relativistic Electrons ◽  
Ion Cyclotron Waves ◽  
Angle Scattering ◽  
Ion Cyclotron ◽  
Electromagnetic Ion Cyclotron Waves

Electron pitch-angle diffusion driven by oblique whistler-mode turbulence

1971 ◽  
Vol 6 (3) ◽  
pp. 589-606 ◽  
Author(s):  
L. R. Lyons ◽  
R. M. Thorne ◽  
C. F. Kennel
Keyword(s):  
Wave Energy ◽  
Diffusion Coefficients ◽  
Pitch Angle ◽  
High Energy ◽  
Harmonic Number ◽  
General Description ◽  
Linear Diffusion ◽  
Whistler Mode ◽  
Angle Scattering ◽  
Cyclotron Harmonic

A general description of cyclotron harmonic resonant pitch-angle scattering is presented. Quasi-linear diffusion coefficients are prescribed in terms of the wave normal distribution of plasma wave energy. Numerical computations are performed for the specific case of relativistic electrons interacting with a band of low frequency whistler-mode turbulence. A parametric treatment of the wave energy distribution permits normalized diffusion coefficients to be presented graphically solely as a function of the electron pitch-angle.The diffusion coefficients generally decrease with increasing cyclotron harmonic number. Higher harmonic diffusion is insignificant at very small electron pitch-angles, but becomes increasingly important as the pitch-angle increases. One thus expected the rate of pitch-angle scattering to decrease with increasing electron energy, since the resonant value of the latter varies proportionately with harmonic number. This indicates that, in mirror-type magnet field geometrics, such as the Earth's radiation belts, the diffusion losses of high energy electrons are likely to be appreciably slower than those at low energy. Integration of the diffusion rates along a complete bounce orbit will be required to clarify this point, however, since the high-energy particles will be subject to more rapid first harmonic diffusion near their mirror points.

scholarly journals Diffusion of Cosmic Rays in MHD Turbulence with Magnetic Mirrors

2021 ◽  
Vol 923 (1) ◽  
pp. 53
Author(s):  
Alex Lazarian ◽  
Siyao Xu
Keyword(s):  
Cosmic Rays ◽  
Diffusion Coefficients ◽  
Pitch Angle ◽  
Mirror Reflection ◽  
Mhd Turbulence ◽  
Magnetic Mirrors ◽  
Parallel Diffusion ◽  
Angle Scattering ◽  
Small Pitch ◽  
New Type

Abstract As the fundamental physical process with many astrophysical implications, the diffusion of cosmic rays (CRs) is determined by their interaction with magnetohydrodynamic (MHD) turbulence. We consider the magnetic mirroring effect arising from MHD turbulence on the diffusion of CRs. Due to the intrinsic superdiffusion of turbulent magnetic fields, CRs with large pitch angles that undergo mirror reflection, i.e., bouncing CRs, are not trapped between magnetic mirrors, but move diffusively along the turbulent magnetic field, leading to a new type of parallel diffusion, i.e., mirror diffusion. This mirror diffusion is in general slower than the diffusion of nonbouncing CRs with small pitch angles that undergo gyroresonant scattering. The critical pitch angle at the balance between magnetic mirroring and pitch-angle scattering is important for determining the diffusion coefficients of both bouncing and nonbouncing CRs and their scalings with the CR energy. We find nonuniversal energy scalings of diffusion coefficients, depending on the properties of MHD turbulence.

Nongyroresonant Pitch Angle Scattering

1999 ◽  
Vol 518 (2) ◽  
pp. 974-984 ◽  
Author(s):  
B. R. Ragot
Keyword(s):  
Pitch Angle ◽  
Angle Scattering
Sign in / Sign up

Export Citation Format

Share Document