Theoretical Studies in Plasmas: Crossed-Field Devices and Ionospheric Plasmas

Crossed-field devices: The Item A.(i) has been done and a manuscript was published in the Journal of Plasma Physics. This is a summary of the current understanding of the physics behind the operation of the non-relativistic devices. On Item A.(ii), a manuscript was published in the proceedings of the SPIE Orlando meeting in April, 2001. This treatment was for a planar device, operating in the same general parameter regime as the A6 magnetron. Work has been, completed on the relativistic cylindrical model of the A6 magnetron. A manuscript is being prepared to detail these results. On Item A, (iii), in an unpublished effort, we have also reviewed further the effect that the relativistic corrections would have on the non-relativistic T266 of CPI. We found that these corrections are rather small, as one would expect. A result from the relativistic electromagnetic model is that, strictly speaking, a two-dimension model of a crossed field device is not valid, unless such a device is either infinitesimally thin or operating in a stationary mode. How thin is thin for computational purposes, has not been determined. Further comments will be made below. Work has continued on the saturated operating stage. A relativistic cylindrical version, has been obtained with the aid of MACSYMA. However, the expressions are sufficiently complex that it was determined that we should first, study the simpler non-relativistic planar model of the T266, as an initial numerical study of this stage of operation. What we have observed is that our model of the relativistic cylindrical AG magnetron indicates the A6 to be potentially more unstable in the saturated operating stage, than the T266 was. This instability would show up as a breakdown in the coherent transfer of electrons from the cathode to the anode.