SMES coil configurations with reduced stray field

The stray field of SMES restricts its site location, although SMES has an a ttractive potential for power management and quality control, The stray fie ld outside a solenoid is analyzed by a series of Legendre polynomials, and the result is applied to the stray fields of various SMES coil configuratio ns. As long as the summation of magnetic moments from all coils is zero, th e term of a stray field decreasing as r(p)(-3) can be cancelled out. The hi gher order of the stray field can vanish if the coil arrangement is optimiz ed. In this paper we consider a single solenoid as a reference, active shie ld coils, axially displaced coils and multipole coil to reduce the stray fi eld. The multipole coil configuration has high potential to drop the stray field, since the stray field behaves like r(p)(-(3+n/2)), where n is the co il number.