Spatial Electron Cyclotron Damping

<jats:p>Spatial electron cyclotron damping in an infinite uniform Vlasov plasma is examined. It is found that the plasma response to a steady-state transverse excitation consists of several terms (dielectric-pole, free-streaming, and branch-cut), but that the cyclotron-damped pole term is the dominant term for z&gt;l≈c/ωce provided (ωpe/ωce)2(c/a)≫1 (where c is the velocity of light, a is the electron thermal velocity, ωpe is the electron plasma frequency, and ωce is the electron cyclotron frequency). If the latter inequality does not hold, then the free-streaming and branch-cut terms persist well past z = c/ωce as ω1 approaches ωce, making experimental measurement of cyclotron damping essentially impossible. Considering only (ωpe/ωce)2 × (c/a)≫1, the effects of collisions and of a finite-width excitation are investigated. Criteria are established concerning collisional damping, measurable damping length sizes, and allowed uncertainty in the magnetic field B0. Results of numerical calculations, showing the regions in the appropriate parameter spaces that meet these criteria, are presented. From these results, one can determine the feasibility of, or propose parameter values for, an experiment designed to measure spatial electron cyclotron damping. It is concluded that the electron temperature Te should be at least 1 eV, and preferably 10 eV or higher, for a successful experiment.</jats:p>