TY  - JOUR
A1  - Vafin, Sergei
A1  - Riazantseva, M.
A1  - Yoon, P. H.
T1  - Kinetic Features in the Ion Flux Spectrum
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - An interesting feature of solar wind fluctuations is the occasional presence of a well-pronounced peak near the spectral knee. These peaks are well investigated in the context of magnetic field fluctuations in the magnetosheath and they are typically related to kinetic plasma instabilities. Recently, similar peaks were observed in the spectrum of ion flux fluctuations of the solar wind and magnetosheath. In this paper, we propose a simple analytical model to describe such peaks in the ion flux spectrum based on the linear theory of plasma fluctuations. We compare our predictions with a sample observation in the solar wind. For the given observation, the peak requires similar to 10 minutes to grow up to the observed level that agrees with the quasi-linear relaxation time. Moreover, our model well reproduces the form of the measured peak in the ion flux spectrum. The observed lifetime of the peak is about 50 minutes, which is relatively close to the nonlinear Landau damping time of 30-40 minutes. Overall, our model proposes a plausible scenario explaining the observation.
KW  - instabilities
KW  - solar wind
KW  - turbulence
KW  - waves
Y1  - 2017
U6  - https://doi.org/10.3847/1538-4357/aa9519
SN  - 0004-637X
SN  - 1538-4357
VL  - 850
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -