  A central issue in the design of tokamaks or stellarators is the coils that
produce the external magnetic fields. The freedom that remains unstudied in the
design of coils is enormous. This freedom could be quickly studied
computationally at low cost with high reliability. In particular, the space
between toroidal field or modular coils that block access to the plasma chamber
could be increased by a large factor. This paper explains how this could be
done using the concept of current-potential patches that was developed in Todd
Elder's thesis.
