Magnetic flux shielding for the precision muon g-2 storage ring superconducting inflector

A muon g-2 experiment (E821) at the AGS requires knowledge of the magnetic field over muon orbits at the level of 0.1 ppm. The superconducting inflector involves a double cosine theta winding; this design approximately cancels its fringe field. Nevertheless its residual field would effect the homogeneity of the storage ring magnetic field. A method of using a superconducting sheet surrounding the inflector to further reduce the fringe field was proposed by one of the authors, W. Meng. An experimental program to explore this technique is described. Part of the test results are presented. >