Improved n=1 Empirical Error Field Penetration Threshold Scaling with Ohmic and L-Mode Conventional Tokamak Plasma Discharges

TL;DR

This paper updates the error field penetration threshold scaling for n=1 modes in tokamaks, using expanded data and focusing on Ohmic and L-mode discharges to improve predictive confidence for future device design.

Contribution

It introduces a refined scaling law based on an expanded database, reducing uncertainty and enhancing reliability for tokamak error field tolerance predictions.

Findings

Scaling law fit quality improved over previous models.

Inclusion of J-TEXT and JET data enhances accuracy.

Predicts the most dangerous error field regime in L-mode plasmas.

Abstract

This paper presents an updated n=1 error field penetration threshold scaling, which increases fit quality compared to previous error field scaling laws, is produced from an expanded database, and exhibits reduced uncertainty in projections to future conventional tokamaks. It improves confidence in tokamak engineering tolerances, which are a significant driver of cost and time constraints on device construction. We add J-TEXT data, new JET data, and create the scaling using only conventional tokamak Ohmic and L-mode experiments. Since H-mode plasmas are more resilient to error field penetration, this scaling predicts what is likely the most dangerous regime of error field penetration for new tokamak designs. These decisions improve confidence in the error field penetration threshold scaling and its application in the construction and design decisions of any future conventional tokamak or FPP.