Open AccessAstrophysical particle acceleration in geospace and beyond
Author(s) -
Horwitz J. L.,
Gallagher D. L.,
Perez J.,
Lieu R.,
Mlller J.A.,
Preece R.
Publication year - 2003
Publication title -
eos, transactions american geophysical union
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.316
H-Index - 86
eISSN - 2324-9250
pISSN - 0096-3941
DOI - 10.1029/2003eo110005
Subject(s) - physics , charged particle , particle acceleration , cosmic ray , electron , solar energetic particles , acceleration , range (aeronautics) , van allen radiation belt , electric field , particle radiation , computational physics , magnetic field , particle (ecology) , astrophysics , plasma , magnetosphere , solar wind , ion , nuclear physics , classical mechanics , coronal mass ejection , aerospace engineering , oceanography , geology , quantum mechanics , engineering
Natural acceleration of charged particles occurs within a variety of physical contexts and through a range of physical processes. “Cosmic” charged particle acceleration can involve particle energies and energy changes from less than one electron Volt (eV),and on through kilovolt (keV) energies,up to 10 18 and perhaps 10 20 eV These acceleration processes can be in the forms of various types of electric fields directed parallel to the magnetic field lines, which are believed chiefly responsible for the energization of the auroral electrons which bombard the Earth's upper atmospheres at high magnetic latitudes to create auroras. There are also “collisionless” shock layers in our interplanetary space and well beyond, to energize charged particles in solar and stellar winds. And there may be exotic—and somewhat speculative—processes such as the effect of intense radiation beams associated with non‐thermal compact objects, or unipolar electric fields of huge magnitudes near a rotating and accreting black hole. These processes may accelerate particles to even 10 20 eV energies. The propagation of such ultra‐high energy particles in time and space may be severely modified by quantum gravity effects, which are no longer negligible in these extreme situations.