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the area of theoretical plasma dynamics, and will not be attempted here. The approach taken in this study is to simulate hydrogen-uranium mixing in steady flow by using analytical expressions for the hydrogen and uranium density profiles. These expressions contain parameters which can be varied to (1) simulate experimentally measured density distributions, (2) perform parameter studies of the effects of various mixing profiles, or (3) optimize steady flow mixing with respect to nuclear criticality and radiant energy transfer.


Simulation of Hydrogen and Uranium Density Profiles

        The axial flow of uranium will be primarily through the central portion of the cavity, so that the maximum uranium concentration after mixing will be at the cavity center and the minimum concentration at the inner edge of the graphite reflector. Since hydrogen will be injected as an annulus surrounding the uranium, the maximum hydrogen concentration should occur in this annular region and the minimum at the cavity center. Near the exhaust end of the chamber, the distributions may differ quantitatively from those in the main region of the chamber. A pictorial representation of the expected hydrogen and uranium density profiles is shown in Figure 16. The radial uranium profile of this general shape can be described by the symmetric