[en] Among the parameters which need to be specified in the design of the SSC are the cell length (l/sub c/) and the coil diameter (d/sub c/). The quality of the magnetic field of the bending magnets, reflected in both small multipole coefficients and a small sigma for these coefficients, improve as d/sub c/ increases. Similarly the smaller β resulting from a decreased l/sub c/ results in an increased admittance (for a constant size beam pipe). Unfortunately increasing d/sub c/ and/or l/sub c/ would result in increasing the cost of the SSC. It is not only desirable but necessary to understand how the performance of an accelerator depends on d/sub c/ and l/sub c/ so that we can have confidence that the SSC when built will work. It should be straightforward to know whether or not an accelerator, once built, works or not. There are however no well accepted tools or criteria for deciding whether or not a proposed design of an accelerator will provide acceptable performance. This is particularly so in the case of accelerators built of superconducting magnets in which the magnetic field is determined by the current distribution in the coils. 3 figs