Radiative pulsed L-mode operation in ARC-class reactors

• Published in: Nuclear fusion Vol. 62; no. 12; pp. 126036 - 126049
• Main Authors: Frank, S.J., Perks, C.J., Nelson, A.O., Qian, T., Jin, S., Cavallaro, A., Rutkowski, A., Reiman, A., Freidberg, J.P., Rodriguez-Fernandez, P., Whyte, D.
• Format: Journal Article
• Language: English
• Published: IAEA IOP Publishing 01.12.2022
• Subjects: ARC; high-field; L-mode; negative triangularity; pilot plant; reactor design; tokamak
• ISSN: 0029-5515; 1741-4326
• DOI: 10.1088/1741-4326/ac95ac

Abstract A new ARC-class, highly-radiative, pulsed, L-mode, burning plasma scenario is developed and evaluated as a candidate for future tokamak reactors. Pulsed inductive operation alleviates the stringent current drive requirements of steady-state reactors, and operation in L-mode affords ELM-free access to ∼ 90 % core radiation fractions, significantly reducing the divertor power handling requirements. In this configuration the fusion power density can be maximized despite L-mode confinement by utilizing high-field to increase plasma densities and current. This allows us to obtain high gain in robust scenarios in compact devices with P fus > 1000 MW despite low confinement. We demonstrate the feasibility of such scenarios here; first by showing that they avoid violating 0D tokamak limits, and then by performing self-consistent integrated simulations of flattop operation including neoclassical and turbulent transport, magnetic equilibrium, and radiofrequency current drive models. Finally we examine the potential effect of introducing negative triangularity with a 0D model. Our results show high-field radiative pulsed L-mode scenarios are a promising alternative to the typical steady state advanced tokamak scenarios which have dominated tokamak reactor development.