A unified transport equation for both cosmic rays and thermal particles

L. L. Williams, N. Schwadron, J. R. Jokipii, T. I. Gombosi

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


We present a unified transport equation that is valid for particles of all energies if the particle mean free paths are much smaller than macroscopic fluid length scales. If restricted to particles with random speeds much greater than fluid flow speeds, this equation reduces to the previously discussed extended cosmic-ray transport equation. It is significant that this allows one to describe the acceleration of particles from thermal energies to cosmic-ray energies using one transport equation. This is in contrast to previous transport equations (the Parker equation and the extended cosmic-ray transport equation), which were restricted to fast particles. The close connection to the extended cosmic-ray transport equation is demonstrated.

Original languageEnglish (US)
Pages (from-to)L79-L81
JournalAstrophysical Journal
Issue number2 PART 2
StatePublished - Mar 10 1993


  • Acceleration of particles
  • Cosmic rays

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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