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Physical Sciences and Mathematics Commons

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Astrophysics and Astronomy

2004

Cosmic Rays

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Nonlinear Parallel And Perpendicular Diffusion Of Charged Cosmic Rays In Weak Turbulence, Andreas Schalchi, John William Bieber, William H. Matthaeus, Gang Qin Nov 2004

Nonlinear Parallel And Perpendicular Diffusion Of Charged Cosmic Rays In Weak Turbulence, Andreas Schalchi, John William Bieber, William H. Matthaeus, Gang Qin

Aerospace, Physics, and Space Science Faculty Publications

The problem of particle transport perpendicular to a magnetic background field is well known in cosmic-ray astrophysics. Whereas it is widely accepted that quasi-linear theory (QLT) of particle transport does not provide the correct results for perpendicular diffusion, it was assumed for a long time that QLT is the correct theory for parallel diffusion. In the current paper we demonstrate that QLT is in general also incorrect for parallel particle transport if we consider composite turbulence geometry. Motivated through the recent success of the so-called nonlinear guiding center theory of perpendicular diffusion, we present a new theory for parallel and …


Abundances Of Heavy And Ultraheavy Ions In ³He-Rich Solar Flares, Glenn M. Mason, Joseph E. Mazur, Joseph R. Dwyer, Jack Randy Jokipii, Robert E. Gold, Stamatios M. Krimigis May 2004

Abundances Of Heavy And Ultraheavy Ions In ³He-Rich Solar Flares, Glenn M. Mason, Joseph E. Mazur, Joseph R. Dwyer, Jack Randy Jokipii, Robert E. Gold, Stamatios M. Krimigis

Aerospace, Physics, and Space Science Faculty Publications

We have surveyed ³He-rich solar energetic particle (SEP) events over the period 1997 September-2003 April in order to characterize abundances of heavy ions near 400 keV nucleonˉ¹. The first part of the study focuses on 20 distinct SEP events that show the previously observed pattern in which, relative to O, heavy ions through Fe are enriched, with the enrichment increasing with mass. We find that these enrichments are well correlated such that ³He-rich SEP events with high Fe/C also show larger enrichments in other heavy ions. Ultraheavy (UH; taken as 78-220 amu) ions are routinely seen in these events with …