Nonlinear tearing stability analysis of ARC and SPARC using a toroidal Rutherford equation coupled to STRIDE and resistive DCON

Non-linear tearing stability analyses of ARC and SPARC are presented over a range of potential current profiles and wall-stabilization effects. The resilience of these scenarios to transiently seeded magnetic islands is predicted using the minimum marginally-stable island width; the island size at which the intrinsic stability of the equilibrium, measured by toroidal 𝚫`, is surpassed by the neoclassical bootstrap drive (in the worst-case scenario of zero mode rotation and hence no ion polarization current stabilization). Toroidal 𝚫` values from multiple codes including STRIDE, resistive DCON and PEST3 are compared. The effects of shaping, mode coupling and finite thermal transport are being explored in ongoing comparisons between the modified Rutherford equation and full-domain MHD simulations in M3D-C1. This work establishes a tearing-physics workflow with multiple redundant 𝚫` calculations for stability analysis across experimental databases.