Cross-magnetic-field heat conduction in non-neutral plasmas

This Letter discusses cross-magnetic-field collisional heat transport for a non-neutral plasma in the typical operating regime lambda(D) much greater than r(c), where lambda(D) is the Debye length and r(c) is the cyclotron radius. The dominant transport mechanism is the exchange of energy associated with velocity components parallel to the magnetic field. For a thermal gradient scale length L-T greater than or similar to 100 lambda(D), the energy exchange is dominated by interactions between particles separated by O(lambda(D)) and yields a thermal diffusivity X similar to nu(c) lambda(D)(2), where nu(c) = n (v) over bar b(2) is the collision frequency. The diffusivity is even larger for larcrer L-T, where the energy exchange is dominated by the emission and absorption of plasma waves.