A Comparison of VMEC and DESC 3D Equilibrium Codes

3D equilibrium codes are vital for stellarator design and operation, as they provide the base state for experimental plasma operation. High-accuracy equilibria are also necessary for stability studies. Comparisons of two 3D equilibrium codes will be presented. VMEC, which uses a gradient-descent algorithm to reach a minimum-energy plasma state, and DESC, which minimizes the MHD force error in real space directly. Accuracy as measured by final plasma energy and satisfaction of MHD force balance, as well as other metrics, will be presented for each code. Differences between the results and the code methods will be discussed.