9600046 Sanders This U.S.-Brazil collaborative research project will study the time duration of highly deformed configurations of lighter nuclei that are formed in heavy-ion fusion reactions. Together with Alejandro Szanto de Toledo of the Nuclear Physics Department of the Universidade de Sao Paulo, the PI's, Stephen Sanders and Francis Prosser at the University of Kansas, will use the Pelletron at Sao Paulo and the Argonne National Laboratory ATLAS facilities to perform an extended series of sensitive tests to deduce compound nucleus lifetimes from the fluctuation measurements of fission fragments. Fine-step excitation functions of these fission yields will be obtained to evaluate the autocorrelation function. It is expected that the measurements will be effective for lifetimes between 7x10^- 22 sec and 7x10^-21 sec. The projected series of tests will make excellent use of the lower-energy facilities in Sao Paulo, where more beam time is available than would be possible in the US labs. Higher energy experiments will be carried out at Argonne in the US. The proposed work forms a coherent collection of experiments in an area where little data is available and capitalizes on the expertise and facilities of the two countries. A graduate student will also travel to Sao Paulo to participate in the work. ***