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 λDrc, where λD is the Debye length and rc 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 LT100λD, the energy exchange is dominated by interactions between particles separated by O(λD) and yields a thermal diffusivity χ~νcλD², where νc0ex0ex=0ex0exnv̄b² is the collision frequency. The diffusivity is even larger for larger LT, where the energy exchange is dominated by the emission and absorption of plasma waves.