Abstract :
General power theorems for rotational electron beams and some moving plasmas are derived by using three sets of variables: Clebsch variables, Lin´s variables, and polarization variables. In each case, the most general power theorem, with unspecified linear operators, is given and for the polarization-variable case this is specialized to some cases of interest. Unfortunately, the physical interpretation of the variables used is not always clear, and the physically unmeasurable variables may not always behave as measurable ones would, so that the theorems are of limited usefulness.
