The Lithium Vapor Box Divertor
Authors: R. J. Goldston, R. Myers, J. Schwartz
Abstract: It has long been recognized that
volumetric capture of the plasma efflux from a fusion power system
is preferable to its localized impingement on a material surface.
Volumetric capture mitigates both the anticipated very high heat
flux and intense particle-induced damage. Recent projections to a
tokamak demonstration power plant suggest an immense upstream
parallel heat flux, of order 20 GW/m2,
implying that fully detached operation may be a requirement for
the success of fusion power. Building on pioneering work by
Nagayama et al. and by Ono et al., we present here a concept for a
lithium vapor box divertor, in which lithium vapor extracts
momentum and energy from a fusion-power-plant divertor plasma,
using fully volumetric processes. At the projected powers and
pressures this requires a high density of vapor, which must be
isolated from the main plasma. Isolation is achieved through a
powerful differential pumping scheme available only to metal
vapors. The preliminary calculations are encouraging, but much
more work is required to demonstrate the practical viability of
this scheme.
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Submitted to: Physica Scripta
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