Massachusetts Institute of Technology. Plasma Science and Fusion Center, Massachusetts Institute of Technology. Department of Nuclear Science and Engineering, Kuang, A. Q., Cao, N. M., Creely, Alexander James, Dennett, Cody Andrew, Hecla, Jake J., Labombard, Brian, Tinguely, Roy Alexander., Tolman, Elizabeth Ann, Hoffman, Henry, Major, M., Ruiz Ruiz, Juan, Brunner, Daniel Frederic, Grover, P., Laughman, C., Sorbom, Brandon Nils, Whyte, Dennis G., Massachusetts Institute of Technology. Plasma Science and Fusion Center, Massachusetts Institute of Technology. Department of Nuclear Science and Engineering, Kuang, A. Q., Cao, N. M., Creely, Alexander James, Dennett, Cody Andrew, Hecla, Jake J., Labombard, Brian, Tinguely, Roy Alexander., Tolman, Elizabeth Ann, Hoffman, Henry, Major, M., Ruiz Ruiz, Juan, Brunner, Daniel Frederic, Grover, P., Laughman, C., Sorbom, Brandon Nils, and Whyte, Dennis G.
The ARC pilot plant conceptual design study has been extended beyond its initial scope [B. N. Sorbom et al., FED 100 (2015) 378] to explore options for managing ∼525 MW of fusion power generated in a compact, high field (B0 = 9.2 T) tokamak that is approximately the size of JET (R0 = 3.3 m). Taking advantage of ARC's novel design – demountable high temperature superconductor toroidal field (TF) magnets, poloidal magnetic field coils located inside the TF, and vacuum vessel (VV) immersed in molten salt FLiBe blanket – this follow-on study has identified innovative and potentially robust power exhaust management solutions. The superconducting poloidal field coil set has been reconfigured to produce double-null plasma equilibria with a long-leg X-point target divertor geometry. This design choice is motivated by recent modeling which indicates that such configurations enhance power handling and may attain a passively-stable detachment front that stays in the divertor leg over a wide power exhaust window. A modified VV accommodates the divertor legs while retaining the original core plasma volume and TF magnet size. The molten salt FLiBe blanket adequately shields all superconductors, functions as an efficient tritium breeder, and, with augmented forced flow loops, serves as an effective single-phase, low-pressure coolant for the divertor, VV, and breeding blanket. Advanced neutron transport calculations (MCNP) indicate a tritium breeding ratio of ∼1.08. The neutron damage rate (DPA/year) of the remote divertor targets is ∼3–30 times lower than that of the first wall. The entire VV (including divertor and first wall) can tolerate high damage rates since the demountable TF magnets allow the VV to be replaced every 1–2 years as a single unit, employing a vertical maintenance scheme. A tungsten swirl tube FLiBe coolant channel design, similar in geometry to that used by ITER, is considered for the divertor heat removal and shown capable of exhausting divertor heat flux lev, DOE NNSA Stewardship Science Graduate Fellowship (No. DE-NA0002135), National Science Foundation Graduate Research Fellowship (Grant No. DGE1122374)