An Extension of Babinet's Principle

Distinction between shadow and edge effects in heavy-ion elastic angular distributions

“…The modulus ͉f n ͉͑͒ so obtained [10,11] In order to distinguish between shadow and edge or surface effects, we will invoke, by optical analogy, an extension [2] of Babinet's principle, which can be formulated as follows: the Fraunhofer diffraction pattern produced by an opaque screen and the one produced by a narrow slit having the shape of its edge, oscillate "180°out of phase," or in quadrature, i.e., the maxima of one pattern coincides with the minima of the other and vice versa. To verify that this phase rule also holds in heavy-ion scattering, we begin with the expression of the elastic amplitude f͑͒, separated as in Eq.…”

“…is often a source of misinterpretation. So, the aim of the present paper is to propose a model-independent procedure, based on an extension [2] of Babinet's principle, allowing one to decide which of these mechanisms is responsible for the observed scattering patterns.…”