This proposal requests funds to permit Dr. James E. Bayfield and Dr. Richard H. Pratt, Department of Physics and Astronomy, University of Pittsburgh, to pursue with a team of Malaysian scientists led by Dr. Chon Sing Chong, School of Physics, Universiti Sains Malaysia (USM), Penang, Malaysia, for a period of 24 months, a program of cooperative research on threshold region elastic photon atom scattering. The collaborators will use theory and experiment to study the extent to which current models describe elastic photon atom scattering in moderate to high atomic number media. Cross sections will be measured for a variety of elements and scattering angles. These experimentally obtained cross sections will be compared with theoretical predictions. The use of experimental data to improve theoretical models will be explored. Both small angle circular target geometry and transmission type geometry will be utilized in the measurements. This project involves cooperative research of two groups of investigators who have complementary skills and facilities. The experimental group at USM has a background of research in radiation metrology with efforts directed towards obtaining higher precision and more accurate measurement of total interaction coefficients and differential scattering cross sections of photons, in addition to applications-based research. The group at Pittsburgh has considerable involvement in benchmark theoretical calculations. Their interest has been in developing a firm physical understanding of the various possible photon interaction processes at the atomic level. The key collaborators are highly respected scientists who, for a number of years, have cooperated in the field of the research. Their cooperation has been highly successful and has resulted in joint publications in refereed journals. This project is relevant to the objectives of the Science in Developing Countries Program which seeks to increase the level of cooperation between U.S. scientists and engineers and their counterparts in developing countries through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual benefit.
