Feeble magnetic fields generated by thermal charge fluctuations in extended metallic conductors: Implications for electric-dipole moment experiments

A simple formulation for calculating the magnetic field external to an exte nded nonpermeable conducting body due to thermal current fluctuations withi n the body is developed, and is applied to a recent experimental search for the atomic electric-dipole moment (EDM) of Hg-199. It is shown that the th ermal fluctuation field is only slightly smaller in magnitude than other no ise sources in that experiment. The formulation is extended to permeable bo dies, and the implications for general EDM experiments are discussed. [S105 0-2947(99)10408-6].