The objective of this three-year U.S.-Yugoslav cooperative research project in atomic physics between Bogomil Obelic of the Rudjer Boskovic Institute and Mitio Inokuti from Argonne National Laboratory is to study the ionization properties of low-energy photons and charged atomic particles in gases of radiological interest. By observing ionization processes, scientists can learn about specific properties and atomic structure of gases. Furthermore, the proposed investigation has importance for modeling the biological effects of certain types of radiation. A benefit of this international collaboration is the joining of the theoretical expertise of the U.S. scientist with the experimental focus of the Yugoslav investigator. This project was approved by the U.S.-Yugoslav Joint Board on Cooperation in Science and Technology and is supported through a joint fund consisting of matching contributions from the U.S. and Yugoslav governments. The U.S. contribution is provided annually by the Department of State. No NSF funds are involved. The grants are composed principally of Yugoslav dinars and made to the principal Yugoslav institute. Grants include travel for U.S. scientists to Yugoslavia and a modest dollar allowance for Yugoslav scientists' living expenses in the U.S.