Actuator authority budget for growth-rate and shape control

Quantify the actuator-authority budget between vertical-instability growth-rate regulation and boundary-shape regulation for the ARC V3A out-vessel coil geometry.

Background

The controller regulates the vertical growth rate, flux balance, vertical position, and plasma current but does not explicitly regulate separatrix shape. Sustained scenario evolution would therefore require a separate shape-control layer operating alongside the fast growth-rate controller. Because both layers would use the same PF coils, the available voltage and current authority must be apportioned so that shape changes do not prevent rapid vertical-stability correction.

References

Sustained operation or scenario evolution would require a separate shape control layer, and the actuator authority budget between $\gamma_{gr}$ and shape regulation is an open design question for the ARC~V3A coil geometry.

— On the feasibility of model-based feedback control of vertical instability growth rate using out-vessel coils in ARC-like scenarios  (2608.22677 - Kumar et al., 24 Aug 2026) in Section 6, Conclusions