Physics – Plasma Physics
Scientific paper
Dec 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010agufmsh21b1820s&link_type=abstract
American Geophysical Union, Fall Meeting 2010, abstract #SH21B-1820
Physics
Plasma Physics
[7845] Space Plasma Physics / Particle Acceleration, [7851] Space Plasma Physics / Shock Waves
Scientific paper
Voyager observations revealed a complex picture of ion acceleration at the heliospheric termination shock. A number of these observations cannot easily be reproduced with the framework of standard steady-state diffusive shock acceleration theory which is based on the Parker transport equation that is restricted to near isotropic particle distributions. Examples of such observations are highly volatile, strongly anisotropic energetic particle distributions upstream, a surprising high energy peak in the average upstream particle anisotropy, intensity spikes, and multiple power spectral slopes. It will be discussed how many of these observations can be naturally explained in terms of modeling unaccelerated interstellar pickup ion acceleration with a time-dependent focused transport approach at the nearly perpendicular termination shock. The advantages of a focused transport approach, that it contains all the necessary physics for shock acceleration modeling without placing a restriction on the on the magnitude of the pitch-angle anisotropy, will be briefly touched upon. It will be emphasized that a key element in its success is a stochastic treatment of the particle injection speed as a consequence of magnetic field line random walk at the termination shock that randomizes the shock obliquity. The disadvantage is that this approach still neglect phase angle information which is retained in particle simulations. However, this appears not to be a serious limitation. The focused transport model, on the other hand, can potentially be extended to global heliospheric scales, which is difficult to achieve with particle simulations.
le Roux Jakobus A.
Smith Edward
No associations
LandOfFree
Interstellar Pickup Ion Acceleration at the Heliospheric Termination Shock does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Interstellar Pickup Ion Acceleration at the Heliospheric Termination Shock, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Interstellar Pickup Ion Acceleration at the Heliospheric Termination Shock will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1508078