Physics Basis for a Conservative Physics and Conservative Technology Tokamak Power Plant: ARIES-ACT2

Abstract

The conservative physics and conservative technology tokamak power plant ARIES-ACT2 has a major radius of 9.75 m at an aspect ratio of 4.0 and has strong shaping with elongation of 2.2 and triangularity of 0.63. The plasma current is 14 MA, and the toroidal field at the plasma major radius is 8.75 T, making the maximum field at the toroidal field coil 16 T. The no-wall β_N reaches ∼2.4, limited by n = 1 external kink mode, and can be extended to 3.2 with a stabilizing shell behind the ring structure shield. The bootstrap current fraction is 77% with a q₉₅ of 8.0, requiring ∼4.0 MA of external current drive. This current is supplied with 30 MW of ion cyclotron radio frequency/fast wave and 80 MW of negative ion neutral beams. Up to 1.0 MA can be driven with lower hybrid (LH) with no wall, and 1.5 or more MA can be driven with a stabilizing shell. Electron cyclotron was examined and is most effective for safety factor control over ρ ∼0.2 to 0.6 with 20 MW. The pedestal density is ∼0.65 × 10²⁰/m³, and the temperature is ∼9.0 keV. The H₉₈ factor is 1.25, n/n_Gr = 1.3, and the net power to LH threshold power is 1.3 to 1.4 in the flattop. Because of the high toroidal field and high central temperature, the cyclotron radiation loss was found to be high depending on the first-wall reflectivity.