Investigating Alfven eigenmodes in ARC and SPARC scenarios using FAR3D

The ARC fusion power plant is a compact design for which the underlying principles will soon be demonstrated by the SPARC tokamak. These projects are being led by Commonwealth Fusion Systems (CFS) in Devens, MA. ARC and SPARC are projected to achieve fusion gains of Q ≃ 50 [1] and Q ≃ 10 [2] respectively. At these gains, a burning plasma will be present in which DT-fusion alpha particles are the dominant source of heating. Understanding the stability of Alfven Eigenmodes (AEs) is crucial for the operation of tokamaks, especially in scenarios involving burning plasmas where alpha particles can drive instabilities. These AE instabilities can lead to confinement losses and reduced plasma performance. This poster investigates the stability of AEs in ARC and SPARC scenarios using the linear FAR3D code [3]. Simulations will scan over toroidal mode numbers for AEs and alpha profiles for different Q values. These simulated AE instabilities will identify how knowledge gained from SPARC's experimental AE stability can be extrapolated to ARC. This understanding will help identify potential challenges and solutions for maintaining AE stability in a fusion power plant.

[1] Creely, A.J., et al. APS DPP 2021

[2] Creely, A.J., et al. Journal of Plasma Physics 2020.

[3] Varela, J., et al. Nucl. Fusion 2017.