In this work we consider the free boundary inverse equilibrium problem for 3D ideal MHD. We review boundary conditions for both fixed and free boundary solutions and under what circumstances a sheet current may exist at the plasma-vacuum interface. We develop an efficient and accurate algorithm for computing the residual of these boundary conditions and use it to compute free boundary equilibria in the DESC code both in vacuum and at finite plasma beta, with and without sheet currents.

翻译：本文研究了三维理想磁流体动力学的自由边界逆平衡问题。我们回顾了固定边界与自由边界解所对应的边界条件，并分析了在何种情况下等离子体-真空界面处可能存在面电流。我们开发了一种高效精确的算法来计算这些边界条件的残差，并利用该算法在DESC代码中分别计算了真空与有限等离子体β条件下的自由边界平衡状态，同时涵盖了存在与不存在面电流的两种情况。