Determination of the sequence and thicknesses of multilayers in an easel painting

In this article we propose the application of an improved algorithm to determine the sequence and the thicknesses of paint multilayers. The concentration profiles of colour pigments are deduced using the PIXE technique for different proton energies on the AGLAE accelerator (LRMF, Le Louvre). As an example, this technique has been applied to an actual easel painting worked out at the Ecole du Louvre. The sequence of the paint layers was unknown to the experimentalists, but had been noted by the painter in the course of her work. The mathematical procedure and some results are presented, which are fully confirmed by the artist. (C) 1999 Elsevier Science B.V. All rights reserved.