Brian Reville (UCD School of Mathematical Sciences)

will speak on

Cosmic ray current driven instabilities and particle transport properties in turbulent self excited magnetic fields.

Time: 2:00PM
Date: Tue 1st May 2007
Location: CASL Seminar Room - Belfield Office Park [map]

Further information

Abstract: It has long been known theoretically that cosmic rays streaming along
the mean magnetic field excite resonant hydromagnetic waves which
scatter and isotropise the particles themselves. The resulting generated
turbulence is believed to saturate at quasilinear levels. However,
in recent years there has been an increase in the study of magnetic
field amplification near collisionless shocks in astrophysics, the sites
where cosmic rays are widely believed to be produced. Observational
evidence suggests that magnetic fields well in excess of the compressed
interstellar medium field are present in many nearby young supernova
remnants, suggesting that there must be some nonlinear process
amplifying the turbulence to values greater than the mean field. The so
called Bell-type MHD instability is reviewed and extended to include a
full plasma kinetic description including thermal effects. The results
from numerical MHD simulations of the instability are presented, and the
resulting particle transport properties in the amplified field is also
shown.

(This talk is part of the CASL Computational Science series.)

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