Derivation of diffraction coefficients for a thin wire of finite length

The scattering from a thin wire of halflength H is described by a simple ray theory. The diffraction coefficients are determined by comparing the expression obtained by the ray approach with a simplified formula derived by one of the classical field approaches. An unusual property of the diffraction coefficients derived is that they depend on a nonlocal property of the diffracting object, namely on the length of the wire.