A numerical study of the pitch-angle scattering of cosmic rays

1982 ◽  
Vol 254 ◽  
pp. 398 ◽  
Author(s):  
J. Kota ◽  
J. R. Jokipii ◽  
D. A. Kopriva ◽  
T. I. Gombosi ◽  
A. J. Owens ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Pitch Angle ◽  
Numerical Study ◽  
Angle Scattering

scholarly journals The Fokker-Planck Coefficient for Pitch-Angle Scattering of Cosmic Rays

1974 ◽  
Vol 190 ◽  
pp. 417 ◽  
Author(s):  
L. A. Fisk ◽  
M. L. Goldstein ◽  
A. J. Klimas ◽  
G. Sandri
Keyword(s):  
Cosmic Rays ◽  
Pitch Angle ◽  
Angle Scattering ◽  
Fokker Planck

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

Numerical Study of Pitch Angle on H-Type Vertical Axis Wind Turbine

2012 ◽  
Vol 499 ◽  
pp. 259-264
Author(s):  
Qi Yao ◽  
Ying Xue Yao ◽  
Liang Zhou ◽  
S.Y. Zheng
Keyword(s):  
Wind Turbine ◽  
Pitch Angle ◽  
Numerical Study ◽  
Vertical Axis ◽  
Azimuth Angle ◽  
Power Coefficient ◽  
Cfd Model ◽  
Vertical Axis Wind Turbine ◽  
Sliding Mesh ◽  
Mesh Technique

This paper presents a simulation study of an H-type vertical axis wind turbine. Two dimensional CFD model using sliding mesh technique was generated to help understand aerodynamics performance of this wind turbine. The effect of the pith angle on H-type vertical axis wind turbine was studied based on the computational model. As a result, this wind turbine could get the maximum power coefficient when pitch angle adjusted to a suited angle, furthermore, the effects of pitch angle and azimuth angle on single blade were investigated. The results will provide theoretical supports on study of variable pitch of wind turbine.

scholarly journals Resonant scattering of energetic electrons in the plasmasphere by monotonic whistler-mode waves artificially generated by ionospheric modification

2014 ◽  
Vol 32 (5) ◽  
pp. 507-518 ◽  
Author(s):  
S. S. Chang ◽  
B. B. Ni ◽  
J. Bortnik ◽  
C. Zhou ◽  
Z. Y. Zhao ◽  
...  
Keyword(s):  
Test Particle ◽  
Pitch Angle ◽  
Low Frequency ◽  
Resonant Scattering ◽  
High Energy ◽  
Whistler Waves ◽  
Energetic Electrons ◽  
High Energy Electrons ◽  
Angle Scattering ◽  
Vlf Waves

Abstract. Modulated high-frequency (HF) heating of the ionosphere provides a feasible means of artificially generating extremely low-frequency (ELF)/very low-frequency (VLF) whistler waves, which can leak into the inner magnetosphere and contribute to resonant interactions with high-energy electrons in the plasmasphere. By ray tracing the magnetospheric propagation of ELF/VLF emissions artificially generated at low-invariant latitudes, we evaluate the relativistic electron resonant energies along the ray paths and show that propagating artificial ELF/VLF waves can resonate with electrons from ~ 100 keV to ~ 10 MeV. We further implement test particle simulations to investigate the effects of resonant scattering of energetic electrons due to triggered monotonic/single-frequency ELF/VLF waves. The results indicate that within the period of a resonance timescale, changes in electron pitch angle and kinetic energy are stochastic, and the overall effect is cumulative, that is, the changes averaged over all test electrons increase monotonically with time. The localized rates of wave-induced pitch-angle scattering and momentum diffusion in the plasmasphere are analyzed in detail for artificially generated ELF/VLF whistlers with an observable in situ amplitude of ~ 10 pT. While the local momentum diffusion of relativistic electrons is small, with a rate of < 10−7 s−1, the local pitch-angle scattering can be intense near the loss cone with a rate of ~ 10−4 s−1. Our investigation further supports the feasibility of artificial triggering of ELF/VLF whistler waves for removal of high-energy electrons at lower L shells within the plasmasphere. Moreover, our test particle simulation results show quantitatively good agreement with quasi-linear diffusion coefficients, confirming the applicability of both methods to evaluate the resonant diffusion effect of artificial generated ELF/VLF whistlers.

scholarly journals Simultaneous Observations of Electromagnetic Ion Cyclotron (EMIC) Waves and Pitch Angle Scattering During a Van Allen Probes Conjunction

2020 ◽  
Vol 125 (4) ◽  
Author(s):  
K. Sigsbee ◽  
C. A. Kletzing ◽  
J. B. Faden ◽  
A. N. Jaynes ◽  
G. D. Reeves ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Angle Scattering ◽  
Van Allen Probes ◽  
Ion Cyclotron ◽  
Emic Waves
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