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Title: INTERSTELLAR PICKUP ION ACCELERATION IN THE TURBULENT MAGNETIC FIELD AT THE SOLAR WIND TERMINATION SHOCK USING A FOCUSED TRANSPORT APPROACH

Journal Article · · Astrophysical Journal
; ;  [1]
  1. Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

We study the physics of locally born interstellar pickup proton acceleration at the nearly perpendicular solar wind termination shock (SWTS) in the presence of a random magnetic field spiral angle using a focused transport model. Guided by Voyager 2 observations, the spiral angle is modeled with a q -Gaussian distribution. The spiral angle fluctuations, which are used to generate the perpendicular diffusion of pickup protons across the SWTS, play a key role in enabling efficient injection and rapid diffusive shock acceleration (DSA) when these particles follow field lines. Our simulations suggest that variation of both the shape ( q -value) and the standard deviation ( σ -value) of the q -Gaussian distribution significantly affect the injection speed, pitch-angle anisotropy, radial distribution, and the efficiency of the DSA of pickup protons at the SWTS. For example, increasing q and especially reducing σ enhances the DSA rate.

OSTI ID:
22679633
Journal Information:
Astrophysical Journal, Vol. 826, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English