AI 中文总结
研究利用平面偶极场线圈，通过单级自由边界优化构建托卡马克-仿星器混合构型，包括真空和有限β情况，能产生多种有利平衡，可实现β提升和场周期变化，类TO构型在大旋转变换时表现良好，为优化有限β混合构型提供平台。
AI 中文摘要
托卡马克-仿星器混合装置旨在将托卡马克式的紧凑性和约束与仿星器式的外部产生的旋转变换和稳态运行相结合。在这项工作中，我们基于最近使用平面偶极场线圈（PDC）的托卡马克-仿星器混合研究。通过对线圈电流和等离子体平衡参数进行单级自由边界优化，构建了真空和有限β构型。真空情况显示出可控的外部变换和磁阱。有限β情况能适应各种密度、温度和压力分布，产生具有自洽自举电流、良好的Mercier稳定性且对外部电流驱动需求降低的准轴对称（QA）平衡。重新优化可实现β提升，并通过适度改变线圈电流进入不同场周期的QA分支。在大旋转变换时，即使未直接优化气球稳定性，类环向全向（TO）构型也比具有匹配分布的QA参考构型表现出更有利的无限n理想气球行为。这些结果表明，PDC为实现优化的有限β混合构型提供了一个灵活的平台。
英文摘要
Tokamak--stellarator hybrids seek to combine tokamak-like compactness and confinement with stellarator-like externally generated rotational transform and steady-state operation. In this work, we build on the recent tokamak--stellarator hybrid study using planar dipole-field coils (PDCs) [Yu et al., arXiv:2605.03599], in which the fixed-position, programmable coils on an axisymmetric winding surface generate flexible three-dimensional shaping fields. Using single-stage free-boundary optimization of coil currents and plasma-equilibrium parameters, we construct vacuum and finite-$β$ configurations. The vacuum cases show controllable external transform and magnetic well. The finite-$β$ cases accommodate various density, temperature, and pressure profiles, producing quasi-axisymmetric (QA) equilibria with self-consistent bootstrap current, favorable Mercier stability, and reduced demand for external current drive. Re-optimization enables $β$ ramp-up and access to different field-period QA branches with moderate coil-current changes. At large rotational transform, a toroidally omnigenous (TO)-like configuration exhibits more favorable infinite-$n$ ideal-ballooning behavior than a QA reference with matched profiles, even though ballooning stability is not directly optimized for. These results demonstrate that PDCs provide a flexible platform for achieving optimized finite-$β$ hybrid configurations.
