Abstract
tAn accelerated fusion energy development program, a “fast-track” approach, requires proceeding witha nuclear and materials testing program in parallel with research on burning plasmas, ITER. A FusionNuclear Science Facility (FNSF) would address many of the key issues that need to be addressed priorto DEMO, including breeding tritium and completing the fuel cycle, qualifying nuclear materials forhigh fluence, developing suitable materials for the plasma-boundary interface, and demonstrating powerextraction. The Advanced Tokamak (AT) is a strong candidate for an FNSF as a consequence of its maturephysics base, capability to address the key issues, and the direct relevance to an attractive target powerplant. The standard aspect ratio provides space for a solenoid, assuring robust plasma current initiation,and for an inboard blanket, assuring robust tritium breeding ratio (TBR) >1 for FNSF tritium self-sufficiencyand building of inventory needed to start up DEMO. An example design point gives a moderate sized Cu-coil device with R/a = 2.7 m/0.77 m, = 2.3, BT= 5.4 T, IP= 6.6 MA, ˇN= 2.75, Pfus= 127 MW. The modestbootstrap fraction of fBS= 0.55 provides an opportunity to develop steady state with sufficient currentdrive for adequate control. Proceeding with a FNSF in parallel with ITER provides a strong basis to beginconstruction of DEMO upon the achievement of Q ∼ 10 in ITER.