Authors: Saul L., Möbius E., Smith C.W., Bochsler P., Grünwaldt H., Klecker B., Ipavich F.
Reference: Geophys. Res. Lett. 31, L05811 10.1029/2003GL019014 (2004)
A statistical analysis of interstellar He+ pickup ion measurements from SOHO/CTOF combined with magnetic field data from WIND/MFI enable quantitative study of wave-particle interactions in the inner heliosphere for the first time. Magnetic field vector measurements with a time resolution of 3 seconds are used to determine power spectrum characteristics of interplanetary magnetic turbulence. These spectral characteristics are then compared in superposed epoch and correlation analyses with He+ fluxes and spectra. The observed pickup ion velocity distributions can be explained consistently as a consequence of pitch angle scattering of the interstellar pickup ions by Alfvenic fluctuations.