Stochastic Ion Heating at the Magnetopause due to Kinetic Alfven Waves

Johnson, Jay R. ; Cheng, C.Z.

Princeton University. Plasma Physics Laboratory.

关键词: Magnetopause;    Heating;    Amplitudes;    Ion Mobility;    71 Classical And Quantum Mechanics, General Physics;   

DOI  :  10.2172/787902
RP-ID  :  PPPL-3596
RP-ID  :  AC02-76CH03073
RP-ID  :  787902

美国|英语

来源: UNT Digital Library

【 摘 要 】

The magnetopause and boundary layer are typically characterized by large amplitude transverse wave activity with frequency below the ion cyclotron frequency. The signatures of the transverse waves suggest that they are kinetic Alfven waves with wavelength on the order of the ion gyroradius. We investigate ion motion in the presence of large amplitude kinetic Alfven waves with wavelength the order of rho(subscript ''i'') and demonstrate that for sufficiently large wave amplitude (delta B(subscript ''perpendicular'')/B(subscript ''0'') > 0.05) the particle orbits become stochastic. As a result, low energy particles in the core of the ion distribution can migrate to higher energy through the stochastic sea leading to an increase in T(subscript ''perpendicular'') and a broadening of the distribution. This process can explain transverse ion energization and formation of conics which have been observed in the low-latitude boundary layer.