Department News

BC Physics researcher’s work presented in the PRL cover article

June 10, 2009

A team consisting of BC Distinguished Research Professor Gabor Kalman and his collaborators from the University of California at San Diego and from LeMoyne College, Syracuse published a paper on the properties of a beam-complex plasma system in a 2D Yukawa lattice of mesoscopic grains, in the recent issue of Physical Review Letters. They have shown that such a system dominated by strong interaction, in contrast to Vlasov plasmas, can develop unique features.

Polar diagram of instability locations in wave vector space for a plasma lattice penetrated by a charged particle beam, for four different beam velocities. The blue lines are longitudinal instabilities, with orange-red for transverse. The instabilities pass through shaded areas denoting gaps (longitudinal blue, transverse pink) where no instability can develop. Image courtesy of G. Kalman.

The researchers predicted remarkable experimentally verifiable effects that distinguish this system from similar, but weakly coupled plasmas: by tuning the system parameters, transverse instabilities can be selectively excited, the excitation spectrum would be highly anisotropic, and one would encounter major gaps in the spectrum where no instability can develop at all.