A Study of Fusion Product Effects in Field-Reversed Mirrors

203 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.The effect of fusion products (fps) on Field-Reversed Mirror (FRM) reactor concepts has been evaluated through the development of two new computer models. The first code (MCFRM) treats fps as test particles in a fixed background plasma, which is represented as a fluid. MCFRM includes a Monte Carlo treatment of Coulomb scattering and thus provides an accurate treatment of fp behavior even at lower energies where pitch-angle scattering becomes important. The second code (FRMOD) is a steady-state, globally averaged, two-fluid (ion and electron), point model of the FRM plasma that incorporates fp heating and ash buildup values which are consistent with the MCFRM calculations. These values are obtained by expressing the fp energy and particle retention in the closed field region in terms of the fraction of marginally confined fps (i.e., those fps that can interact with both the open and closed field plasma but still do not have a "loss cone"). Both codes employ an approximate representation of the field-reversed equilibrium based on Hill's vortex model.These codes have been used extensively in the development of an advanced-fuel FRM reactor design (SAFFIRE). These studies show that a significant amount of fp energy (and associated ash) deposition occurs in the closed field region of the FRM, despite the relative small size of the plasma (radius equal (TURN) 5 to 15 ion gyroradii). Typically 50% of the fp energy (and the resulting thermal fps) are deposited in the closed field region of the reference SAFFIRE designs. This is particularly important from the standpoint of advanced-fuel operation, where attractive (Q > 10) systems are found within the current "stable" limits on the plasma size, together with the possibility of "ignited" operation if the present stability limits are extended by 50%. These results are illustrated through a discussion of the SAFFIRE reactor optimization studies and through several summaries of reference case reactor parameters. Typical parameters for a D-('3)He type SAFFIRE plant cell are: 2.3 MW from a 3/1 elongated, 21.5-cm mirror radius plasma, with ion and electron temperatures of 80 and 75 keV and a plasma ion density of 4.4 x 10('14)cm('-3). Larger powers can be obtained by stacking cells.A Catalyzed-D version of the plant is also discussed along with an investigation of the steady-state energy distribution of fps in the FRM. User guides for the two computer codes are also included.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD