Systems studies of lower cost ITER options

The tokamak systems code (SuperCode) is used to identify lower-cost ITER options. Superconducting coil, lower-cost options are found by: (1) reducing the ITER technical objectives (e.g., driven burn and lower wall load), (2) using more aggressive physics (advanced physics) assumptions (e.g., higher shaping, better confinement, higher beta, etc.), and (3) more aggressive engineering assumptions (reduced shield/gaps and inductive requirements). Under ITER nominal physics assumptions, but designing for a driven Q = 10 operation results in approximately 30% cost reduction if the required neutron wall load is dropped to 0.5 MW/m². Assuming advanced physics guidelines leads to cost savings of up to 40% in an ignited device with a major radius as low as R = 5.5 m. Designing this device for Q = 10 results in additional cost savings of 10%. If reduced inboard shield and scrapeoff is assumed, and no inductive capability is required, machine size and cost benefits tend to saturate at about R = 5 m and 50% of the ITER-EDA cost.