This award supports cooperative research on theoretical nuclear physics to be carried out by Akif Balantekin, William Friedman and Kirk McVoy of the University of Wisconsin at Madison in collaboration with Brazilian physicists Maria Nemes at the University of Sao Paulo and Carlos Bertulani at the Federal University in Rio de Janeiro. They will study electromagnetic processes in heavy-ion nuclear reactions. The immediate goal of the research is to investigate whether bremsstrahlung radiation carries specific information about the nature of nuclear fragmentation in relativistic heavy-ion reactions. Also to be studied are the limitations of the widely used Williams-Weizacker virtual photon limit of the electromagnetic excitation process by comparing to a fully quantum mechanical treatment. The idea to use bremsstrahlung radiation is a new one so the investigation will prove to be timely and interesting. This work will bring together a team with unique experience on both sides. Besides the mutual benefit to the U.S. and Brazil, this research will be beneficial to the community of nuclear scientists.