Determination of plasma layer properties from the measured electromagnetic transmission coefficient

Several commonly-used approximations of the transmission coefficient of a uniform plasma slab are critically examined and compared with a new approximation developed in this paper. It is shown that the new approximation, in addition to being very suitable for use on digital computers, gives much higher accuracy than any other for most useful values of plasma and collision frequencies. Regions of validity of each approximation are given in the plasma frequency-collision frequency plane for various amounts of error and slab thicknesses.