“Venetian-blind” direct energy converter for fusion reactors

Abstract

A new direct energy conversion technique that uses the angular-dependent transmission of ribbon grids, which resemble Venetian blinds, to recover the energy of particles leaking out of a fusion reactor is discussed. This converter works well, even to energies as low as 10 keV, because of its excellent space-charge handling ability. This low-energy operating range makes direct energy conversion possible on closed confinement devices; operation at about 100 keV might be useful on open confinement devices. Energy recovery efficiencies of 60 to 70% are predicted. Examples are presented in which a direct energy converter with efficiencies in this range, when viewed as a topping cycle to a thermal converter, could considerably improve the reactor prospects of both open- and closed-field-line confinement schemes.

One-Dimensional Semianalytical Model for Optimizing the Standing-Wave Direct Energy Converter

“…Further downstream, decelerator electrodes use the kinetic energy of the ion bunches to excite an oscillating circuit, from which power can be drawn. The TWDEC differentiates itself from other direct energy conversion methods [5] in that it provides its electric power in alternating current (advantageous for the direct drive of proposed radio frequency space propulsion systems [6][7][8]) and can operate at a lower voltage relative to the ion energy than a direct charge capturing system [9]. The mechanism of energy conversion in a TWDEC is analogous to a linear particle accelerator operating in reverse.…”

Meta-material based nuclear structure applications in beamed thrust and space energy harvesting

“…The Venetian Blind direct energy converter concept developed at Lawrence Livermore Laboratory [32] uses ribbon-like surfaces that are more transparent to ions going forward than to ions going backward [33]. Ions pass through surfaces specially coated and processed [34] of successively increasing potential until they turn and start back.…”

Generalities

“…See ; Moir and Barr (1973); Momota et al (1992); Yoshikawa, Noma, and Yamamoto (1992);and Bloch and Jeffries (1950). The conversion of the neutron energy to usable forms has an efficiency of only some 40% because the particles are uncharged and heat management and mechanical heat engines are involved.…”