FIP-P 7 / 21-DEMO DESIGN USING THE SYCOMORE SYSTEM CODE : CONSERVATIVE ASSUMPTIONS AND PATHWAYS TOWARDS THE REACTOR

The SYCOMORE code was used to study DEMO design starting from conservative present-day assumptions then relax the constraints. Present-day assumptions include H-factor=0.9, fGW=0.9, κ95=1.4, Qpeak, target=5MW.m -2, q95=4.0, σstress,TF = 500 Mpa, TBR=1.12, among others. The starting point for a 325 MW net electric power, 2 hours design is a large machine with R/a = (13.5m/5.9m) Relaxing plasma performance constraints (H, fGW, κ95) brings the largest gains although insufficient to bring the major radius below 10 m if taken alone. Technological constraints only become designdriving for higher net electric power (>500 MWe) and/or smaller machines (<10m) Performances become very sensitive to small changes on the assumptions when the size is reduced below 8.50 m. Relaxation of successive constraints. Qpeak becomes a constraint only for higher power devices