What is the outer source of anomalous cosmic rays?

[wolram]

http://www.sciencedaily.com/releases/2002/10/021031071017.htm

ScienceDaily (Oct. 31, 2002) — WASHINGTON - Researchers have found that a portion of anomalous cosmic rays -- charged particles accelerated to enormous energies by the solar wind -- results from interactions with dust grains from a belt of comet-sized objects near Pluto's orbit. These objects make up what is known as the Kuiper Belt, a remnant of the formation of the solar system.

 

[B. Elliott]

Here's the actual Geophysical Research Letters paper...

The Outer Source of Pickup Ions and Anomalous Cosmic Rays

Abstract. The traditionally accepted source of Anomalous Cosmic
Rays (ACRs) is neutral atoms penetrating the heliosphere from
the local interstellar cloud (LIC). The ACR composition should be
depleted in easily ionized atoms such as C, Si, and Fe. However, significant
fluxes of these ions are observed in ACRs and their source
has not been previously identified. We show that there is an “outer
source” of pickup ions, and hence ACRs, caused by sputtered atoms
(subsequently ionized and picked up by the solar wind) from small
grains generated via collisions of objects in the Edgeworth-Kuiper
Belt. The outer source accounts for the abundance and composition
of the additional population of ACRs. The discovery that
ACRs are generated from material in the Edgeworth-Kuiper Belt
provides an exciting new tool for understanding the mass distribution
and composition of the Edgeworth-Kuiper Belt, and for probing
the plasma-dust interactions in stellar environments.

N. A. Schwadron
Southwest Research Institute, San Antonio, Texas
M. Combi
Department of Atmospheric, Oceanic and Space Science, The University of Michigan, Ann Arbor
W. Huebner, D. J. McComas
Southwest Research Institute, San Antonio, Texas

http://people.bu.edu/nathanas/pub/OuterSource.pdf