A dimensionless parameter dependence study of intrinsic torque has been performed on a database of H- and I-mode plasmas from the Alcator C-Mod tokamak. The torque was determined by comparing intrinsic angular momentum density profiles just before and just after L-H and L-I transitions. The intrinsic torque has been found to scale as β1.5Nρ∗-1.0ν∗0.1, with the parameter ranges 0.3 ≤ βN≤ 1.5, 0.004 ≤ρ∗≤ 0.011 and 0.04 ≤ ν∗≤ 0.9. Comparison with results from JET and DIII-D suggests that the intrinsic torque should be normalized by some measure of the device size. Depending upon this normalization, the estimated total intrinsic torques for ITER, SPARC and ARC are ~20, ~4 and ~8 Nm, respectively.
- Intrinsic torque