MCP code fluorescence-routine revision

A new method is described for treating fluorescence, which replaces the original subroutine of the Monte Carlo photon code (MCP), and eliminates its most undesirable features. The major changes include (a) elimination of the very inaccurats 1/E/sup 3/ law for photoelectric cross section, b) updating of relative intensities of K-fluorescence lines, (c) elimination of fluorescence from shells other than K and L, and (d) provision for secondary L-fluorescence. Except for the latter, the previous code is unchanged, as well as the storage format. However, the change in method is reflected in the new constants, which have been completely revised, and are included here in tabulated form. (auth)