Preliminary Analysis of a Large-Scale Helmholtz-Type Direct Energy Converter for a D-3He Fusion Reactor

Abstract

The separation capability of the charged particles is one of the most important capability for the direct energy converter (DEC) of DHe fusion reactors. An alternative DEC using Helmholtz coils (Helmholtz DEC) is designed to reduce the selfinduced electric field and separate charged particles when the thermal input is large as 250MW (220MW/m). Its numerical analyses with a two-dimensional approximation give the following results. (1) The Helmholtz DEC with 10MW (8.8MW/m) thermal input : The induced electric potential distribution is stable. The separation of ions and electrons can reach as high as 99.4% when both electrodes are grounded. When the electric potential is given to both electrodes as 9 patterns, the highest separation rate is about 95%. (2) The comparison of Helmholtz DEC with closer collector-type Cusp DEC : When both electrodes are grounded the separation rate becomes over 95% with both DEC. When the anode is given 100kV the separation is successful with only Helmholtz DEC. (3) The Helmholtz DEC with 250MW thermal input : This is the thermal input planned with ARTEMIS. The separation is successful using Helmholtz DEC. Inside of the DEC, however, the self-induced electric potential is too high to convert the kinetic energy of ions into electricity. Figure 1: D-He Fueled FRC Fusion Reactor ”ARTEMIS” ∗Copyright c °2002 by the American Institute of Aeronautics and Astronautics, Inc. All right reserved. †Senior Member, Professor ‡Member, Emeritus Professor