9618451 Cronin This award supports planning visits to prepare for a worldwide effort organized by Jim Cronin, University of Chicago, to study the highest energy cosmic rays. Plans in the long run include collaboration in building two cosmic ray observatories that will be equipped to study the highest energy cosmic rays in order to understand how protons or nuclei are accelerated to such high energies, and to try to determine the sources of those cosmic rays. This work is expected to address one of the central problems in astrophysics, the origin of cosmic rays. Collaboration with Russian, Japanese and Vietnamese scientists will take place under this grant. Testing of detectors essential to the project will take place in Japan, with the participation of two University of Chicago students. Exchanges of visits between Chicago and Dalat, Vietnam will help initiate cooperation on computer simulation of the detectors. A visit to Chicago by a key Russian scientist will help define the potential for Russian contribution of inexpensive photomultipliers to the project.
