This award will support collaboration between Professor Richard Pratt of the University of Pittsburgh and Professors Solange de Barros and Odair Goncalves of the Federal University of Rio de Janeiro, in cooperation with a physics group at the Federal University of Parana in Curitiba, Brazil. The aim of the research is to conduct experimental and theoretical investigations into the elastic scattering of gamma rays and X-rays from atoms, based on complementary programs at the three above universities. The main focus will be on anomalous scattering (elastic scattering of photons with energies near atomic absorption edges). Understanding the photon scattering process is important in improving the technology base and the basic understanding of atomic and solid-state physics. The project will attempt to identify suitable choices for a critical comparison of theory and experiment. The researchers will study the effects of different atomic potentials and use experimental information to understand the limits of certainty in predictions near atomic edges. Their experimental work will test the validity of these predictions. The theoretical research will be conducted at the University of Pittsburgh. The experimental work will be performed at the Federal University of Rio de Janeiro and the Federal University of Parana.
