Element and isotope separation in a vacuum-arc centrifuge

Abstract

Centrifugal separation of elements and isotopes in a rotating, magnetized column of highly ionized plasma is described. Such a centrifuge differs from prior plasma centrifuges in that the source of plasma is a laser-initiated vacuum arc, rather than a gas discharge. Detailed measurements are presented of the axial evolution of the radial plasma flux and separation profiles. Centrifugal separation increases rapidly with distance from the cathode plasma source, reaching an asymptotic value about 60 cm downstream. The separation is observed to increase exponentially with the square of the radius. The potential profile across the column was measured and found to be parabolic with radius. These observations are accounted for by a steady-state, multispecies, fluid model of the rotating plasma.

Plasma isotope separation methods

“…But once uo = uoc, further increase in the power input only produces additional ionization. The more recent development utilizes a vacuum arc [17]- [20] to produce a fully ionized plasma, and in this way overcomes the AlfvCn limit. Fig.…”

“…Further, the magnetic field is assumed to be axial and uniform, and a constant radial "self-consistant" electric field, E, is assumed to exist. This is due to the ambipolar diffusion of the ions in the radial direction [20], and in turn produces an E, x B, drift or rotation with frequency or the order of E,/B,. A three-component system is considered, composed of electrons, and ions 1 and 2.…”

“…A number of interesting papers have been published dealing with the laser-initiated vacuum arc plasma centrifuge, [17]- [20]. A fully ionized plasma is produced and transported through an axial magnetic field.…”

“…3 is a device used in [16] for generating a rotating plasma in a partially ionized gas, and Fig. 4 corresponds to the system used in [20] to generate a fully ionized plasma. The physical mechanism producing a plasma rotation is the j x B force.…”

“…Here, the parameter 0 represents the ratio of the mass motion energy to the thermal energy of the most abundant species or, as defined in [20]:…”