Investigation of the skin effect in the bulk of electrical conductors with spin-polarized neutron radiography

The skin effect in the bulk of an electrical conductor, i.e., the displacement of the current density from the inner part to the edges of a conductor, was investigated with spatial resolution using spin-polarized neutron imaging. Different current frequencies from 10 to 1000 Hz were applied to a sample. At each frequency the current distribution was analyzed and the influence of the electrical contacts was investigated. The experimental findings are in qualitative agreement with theoretical predictions and prove the suitability of spin-polarized neutron imaging as a unique tool for investigations of current density distributions in bulk materials in general. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2992516]