Physics basis for a reversed shear tokamak power plant

AbstractThe reversed shear plasma configuration is examined as the basis for a tokamak fusion power plant. Analysis of plasma equilibrium and ideal MHD stability, bootstrap current and current drive, plasma vertical stability and position control, divertor physics and plasma power balance are used to determine the operating point parameters that maximize fusion power density and minimize the recirculating power fraction. The final plasma configuration for the ARIES-RS power plant obtains β of 4.96%, plasma driven current fraction of 91%, plasma current of 11.3 MA, toroidal field of 8.0 T and major and minor radius of 5.5 and 1.4 m. The current drive system utilizes fast wave, lower hybrid and high frequency fast wave current drive to obtain maximum current profile flexibility, requiring ≤80 MW of power. A divertor solution is found which employs neon impurity injection to enhance the radiation in the scrape-off layer (SOL) and divertor and results in a combined particle and heat load in the divertor of ≤6 MW m−2. The plasma is driven with a Q of 25 and is at a thermally stable operating point. The plasma is assumed to be in an ELMy H-mode, with low amplitude and high frequency ELMs.