Plasma Centrifuge With Crossed E × B Fields and Thermally Driven Countercurrent Flow

Abstract

It is well established from gas centrifuge (GC) development that isotope separation in a rotating, multispecies gaseous medium increases with axial circulation of the rotating gas in a long separation chamber. This article aims at the development of a commercially viable plasma centrifuge (PC) for specific, nonuranium isotopes. The proposed model PC employs crossed constant radial electric and axial magnetic fields to provide radial separation of a partially ionized gas, combined with a thermal method to establish axial circulation in the rotating medium. The proposed thermal method creates an axial temperature gradient by cooling one end of the separation chamber. By calculation, the inclusion of circulation flow is shown to create axial redistribution of the target component concentration, increasing the longitudinal separation. An analysis of the hydrodynamic and thermal problems is performed for an extended end disk PC in the framework of the boundary layer theory. Radial velocity profiles of the conducting gas in the boundary layer are calculated with respect to the temperature ratio in the external flow ( $T_{1}$ ) and the disk surface ( $T_{0}$ ) for various Prandtl (Pr) numbers. The results demonstrate that for small values of the Pr number, cooling of an end surface within the PC separation chamber results in an intensive inflow of the conducting medium to the solid surface. It is shown that in a PC with crossed fields, cooling one of its ends achieves an effective multiplication of the separation effect along the length of the column.