A PRELIMINARY-STUDY OF A DT TOKAMAK FUSION-REACTOR WITH ADVANCED BLANKET USING THE COMPACT FUSION ADVANCED BRAYTON (CFAB) CYCLE

Preliminary key issues for a synchrotron radiation-enhanced compact fu sion advanced Brayton (CFAB) cycle fusion reactor similar to the CFAR (compact fusion advanced Rankine) cycle reactor are presented. These i nclude plasma operation windows as a function of the first wall reflec tivity and related issues, to estimate an allowance for deterioration of the first wall reflectivity due to dpa effects. It was found theore tically that first wall reflectivities down to 0.8 are still adequate for operation at an energy confinement scaling of 3 times Kaye-Goldsto n. Measurements of the graphite first wall reflectivities at Nagoya Un iversity indicate excellent reflectivities in excess of 90% for CC-312 , PCC-2S, and PD-330S in the submillimeter regime, even at high temper atures in excess of 1000 K. Some engineering issues' inherent to the C FAB cycle are also discussed briefly in comparison with the CFAR cycle which uses hazardous limited-resource materials but is capable of usi ng mercury as coolant for high heat removal. The CFAB cycle using heli um coolant is found to achieve higher net plant conversion efficiencie s in excess 60% using a non-equilibrium magnetohydrodynamic disk gener ator in the moderate pressure range, even at the cost of a relatively large pumping power, and at the penalty of high temperature materials, although excellent heat removal characteristics in the moderate press ure range need to be guaranteed in the future.