Relativistic electron beam driven instabilities in the presence of an arbitrarily oriented magnetic field
2008 (English)In: Physics of Plasmas, ISSN 1070-664X, Vol. 15, no 6, 062102-1- p.Article in journal (Refereed) Published
The electromagnetic instabilities driven by a relativistic electron beam, which moves through a magnetized plasma, are analyzed with a cold two-fluid model. It allows for any angle B between the beam velocity vector and the magnetic field vector and considers any orientation of the wavevector in the two-dimensional plane spanned by these two vectors. If the magnetic field is strong, the two-stream instability dominates if B=0 and the oblique modes grow faster at larger B. A weaker magnetic field replaces the two-stream modes with oblique modes as the fastest-growing waves. The threshold value separating both magnetic regimes is estimated. A further dimensionless parameter is identified, which determines whether or not the wavevector of the most unstable wave is changed continuously, as B is varied from 0 to /2. The fastest growing modes are always found for a transverse propagation of the beam with B=/2, irrespective of the magnetic field strength. ©2008 American Institute of Physics
Place, publisher, year, edition, pages
2008. Vol. 15, no 6, 062102-1- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-42496DOI: 10.1063/1.2926634Local ID: 65120OAI: oai:DiVA.org:liu-42496DiVA: diva2:263353