(Georgia Institute of Technology, 2002-09)
Stacey, Weston M.
A previous model for the calculation of poloidal velocities and poloidal density asymmetries in the core of a tokamak plasma is refined and extended by the inclusion of terms which are important for the calculation of these quantities in the plasma edge. Agreement of predictions of the model with experiment is demonstrated. The effects of edge pressure gradient, collisionality, neutral density and up–down flux surface asymmetry on the edge poloidal rotation velocities are illustrated by a series of model problem calculations.
(Georgia Institute of Technology, 2002-03)
Stacey, Weston M.; Mandrekas, John; Hoffman, E. A. (Elisha Albright); Kessler, G. P.; Kirby, C. M.; Mauer, A. N.; Noble, J. J.; Stopp, D. M.; Ulevich, D. S.
A design concept and the performance characteristics for a fusion transmutation of waste reactor (FTWR)—a sub-critical fast reactor driven by a tokamak fusion neutron source--are presented. The present design concept is based on nuclear, processing and fusion technologies that either exist or are at an advanced stage of development and on the existing tokamak plasma physics database. A FTWR, operating with k[subscript eff] ≤
0.95 at a thermal power output of about 3 GW and with a fusion neutron source operating at Q [subscript p] = 1.5-2, could fission the transuranic content of about a hundred metric tons of spent nuclear fuel per full-power-year and would be self-sufficient in both electricity and tritium production. In equilibrium, a nuclear fleet consisting of LWRs and FTWRs in the electrical power ratio of 3/1 would reduce the actinides discharged from the LWRs in a once-through fuel cycle by 99.4% in the waste stream that must be stored in high-level waste repositories.
(Georgia Institute of Technology, 2002-03)
Stacey, Weston M.; Mandrekas, John
A neoclassical theory of gyroviscous radial momentum transport and poloidal and toroidal rotation has been compared with experiment in DIII-D discharges in different confinement regimes, with a range of neutral beam powers and with co- and counter-injection, and with various types of dominant impurity species present. Calculated central toroidal rotation velocities and momentum confinement times agreed with experiment over a wide range of these conditions, with one notable exception in which a drift correction may be needed to reduce the gyroviscous toroidal force. Radial distributions of toroidal rotation velocities and radial electric field, calculated using the radial distribution of toroidal angular momentum input density, agreed with measured distributions.
(Georgia Institute of Technology, 2002-01-23)
Stacey, Weston M.
A model for the edge pedestal in high-confinement mode tokamak plasmas is described. Separate gradient scale lengths of the density and of the ion and electron temperatures are calculated from transport and atomic physics considerations, and a common pedestal width is calculated from either a magnetohydrodynamic pedestal β-limit or from neutral penetration considerations. Predictions of the model for a representative gas fueled tokamak model problem are discussed vis-à-vis measured values of pedestal gradient scale lengths and widths, ballooning mode limits, and scaling with operational parameters