Computation of Uranium Plasma Composition

        The computation of the uranium plasma composition requires the determination of a consistent relation between (1) the electron fraction (4.23) (or (4.31) for low temperatures), (2) the lowering of the ionization potential (4.38), and (3) the cut-off quantum number (4.40). These expressions are seen to be completely coupled since the plasma composition is dependent on the partition functions, the partition functions are dependent on the effective ionization potentials, and effective ionization potentials are dependent on the plasma composition. The uranium plasma composition is calculated using an iterative technique which searches for the consistent solution of equations (4.23), (4.38), and (4.40). A program called UPLAZ-2* was written to perform these iterative calculations.

        For a given pressure and temperature, the UPLAZ-2 iteration is carred out as follows:

        Step 1.--Starting with equation (4.23), the electron, atom, and ion densities are computed using only the first term (ground state) of (4.39) in the partition functions. These particle densities are used to compute the ionization


        *Details of UPLAZ-2 and other programs written for this study are given in the Appendices.


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