Preliminary analysis of MHD—Brayton cycle applied to fusion reactors (CFAR)

High performance non-equilibrium magnetohydrodynamic (MHD) disk generators applied to fusion reactors are designed and simplified cycle analyses are carried out which show the following. (1) Disk-type MHD generators of high performance can be designed which result in an enthalpy extraction ratio of 50%–57%. The maximum value of magnetic flux density ranges from 5.4 to 7.9 T depending on the maximum temperature of the MHD working gas. (2) Two MHD—Brayton systems are proposed: (a) a simple MHD system and (b) an MHD—gas turbine combined system. The cycle efficiency of the first system ranges from 39.6% to 63.6%, while the second system yields 54.0%–67.8%. The efficiency depends strongly on the maximum temperature of the MHD working gas and on the pressure recovery ratio of the diffuser. (3) A concept of blanket design is briefly described. A detailed study of the overall fusion reactor, including neutronics calculation of the blanket, is required as future work.