To achieve its performance goals, SPARC plans to operate in equilibrium configurations with a strong elongation of , which in turn will destabilize the n = 0 vertical instability. However, SPARC also features a relatively thick conducting wall that is designed to withstand disruption forces, leading to lower vertical instability growth rates than usually encountered. In this work, we use the TokSyS framework to survey families of accessible shapes near the SPARC baseline configuration, finding maximum growth rates in the range of s−1. The addition of steel vertical stability plates has only a modest () effect on reducing the vertical growth rate and almost no effect on the plasma controllability when the full vertical stability system is taken into account, providing flexibility in the plate conductivity in the SPARC design. Analysis of the maximum controllable displacement on SPARC is used to inform the power supply voltage and current limit requirements needed to control an initial vertical displacement of 5% of the minor radius. From the expected spectra of plasma disturbances and diagnostic noise, requirements for filter latency and vertical stability coil heating tolerances are also obtained. Small modifications to the outboard limiter location are suggested to allow for an unmitigated vertical disturbance as large as 5% of the minor radius without allowing the plasma to become limited. Further, investigations with the 3D COMSOL code reveal that strategic inclusion of insulating structures within the VSC supports are needed to maintain sufficient magnetic response. The workflows presented here help to establish a model for the integrated predictive design for future devices by coupling engineering decisions with physics needs.
この論文は、SPARCトカマクの垂直安定性制御に関する研究を報告しています。SPARCは高性能を目指すため強い細長さを持つ平衡状態を計画していますが、これは垂直不安定性を引き起こします。しかし、SPARCは厚い導体壁を持っているため、通常よりも低い成長率になると予想されます。この研究では、SPARCの基準構成近くの形状について調査し、垂直成長率の上限を明らかにしています。また、垂直安定化プレートの効果や、初期垂直変位に対する制御要件についても検討しています。