This award supports ongoing collaboration between Buford Price, University of California at Berkeley, and He Yudong and Jing Guiru, Chinese Institute of Physics, Beijing, on measurement of isotopic abundances of heavy cosmic rays. Using a newly developed track-recording glass detector (BP-1, developed during earlier collaboration), measurements of the isotopic composition of iron and neighboring nuclei in the cosmic radiation will be attempted. The detectors will be flown in a high altitude balloon, yielding tracks of over 1000 cosmic ray nuclei. Data will be analyzed at both Berkeley and Beijing. These measurements of isotopic abundances should tell us about the origin and acceleration of cosmic rays and about how heavy elements are synthesized in very hot, dense, highly evolved stars.
