Error fields from misalignment of the toroidal field (TF) and poloidal field (PF) coils in TPX are presented in terms of the outward normal B-field (B/sub /spl perp//), expanded in poloidal and toroidal harmonics (m, n), on a simulated, D-shaped, plasma flux surface. Results are reported for n=1 toroidal mode number and low poloidal mode numbers, m, and for various displacements of the TF and PF coils. In particular, results are given for the m,n=2,1 error field which interacts with the q=2 surface to cause locked modes and loss of plasma performance. Based on existing experiments, maximum permissible field errors are 4 G for the 2,1 mode and 8 G for the n=1; m=1,3,4 modes. Results are presented for a rigid shift and rotation of a single TF coil and for a rigid, radial shift of each PF coil.
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