In GitLab by @pc6783 on Oct 11, 2021, 15:40
Currently, the PF coil current allocation algorithm for Group 3 (equilibrium and shaping coils) uses a SVD formulation to target the vertical field at the plasma major radius while minimizing the sum of the squares of the PF coil currents. This is good, but it seems to me that this is a very solid foundation on which to include more considerations in the PF coil current allocation.
For a double-null divertor, one could use the existing SVD solver to target two additional field points: Zero (r and z) field at the X-points. You'd need to add the plasma current, which could be approximated as a filament at the major radius. Since the elongation and triangularity determine where the X-points are, this self-consistently folds elongation and triangularity into the current allocation.
Has anyone been looking at the PF coils? What do we think about this plan? I don't see any showstoppers as of yet.
In GitLab by @pc6783 on Oct 11, 2021, 15:40
Currently, the PF coil current allocation algorithm for Group 3 (equilibrium and shaping coils) uses a SVD formulation to target the vertical field at the plasma major radius while minimizing the sum of the squares of the PF coil currents. This is good, but it seems to me that this is a very solid foundation on which to include more considerations in the PF coil current allocation.
For a double-null divertor, one could use the existing SVD solver to target two additional field points: Zero (r and z) field at the X-points. You'd need to add the plasma current, which could be approximated as a filament at the major radius. Since the elongation and triangularity determine where the X-points are, this self-consistently folds elongation and triangularity into the current allocation.
Has anyone been looking at the PF coils? What do we think about this plan? I don't see any showstoppers as of yet.