Expanded Error Field Penetration Threshold Database Scaling with New Unitless Overlap Metric

The ITPA error field penetration scalings have been improved with additional data from JET and J-TEXT, optimized parameterizations, and a new unitless overlap metric. Since even small non-axisymmetric fields can degrade confinement through reconnection and locked mode generation, this scaling provides a critical tool for the design, construction, and operation of future tokamaks. This work expands the ITPA database, particularly in the Bt and q95 ranges for JET and the unique (Bt, R) operational space provided by including J-TEXT. Scalings have been optimized by considering a greater variety of equilibrium parameters for each shot in the database, including the plasma control surface area. A new normalization of the overlap, the metric quantifying how much error field a given plasma can withstand, improves the fitting quality by introducing an explicit plasma area dependence. The new scaling provides an improved fit quality and increase in confidence for projections that can be used to guide the assembly of future tokamaks such as SPARC and ITER.