Cooksey was the son of George Cooksey from Birmingham, England and Linda Dows from New York. After completing high school at the
Thacher School in California, Donald followed his brother Charlton Cooksey, a physics professor at
Yale University. At Yale, he became a physicist specializing in designing and building scientific instruments, especially detectors for measuring sub-atomic particles such as
neutrons. When
Ernest O. Lawrence was at Yale during the 1920s, Cooksey and Lawrence became friends. In 1932, Lawrence moved to Berkeley, California to set up the
Radiation Laboratory. Lawrence asked Cooksey to come to Berkeley to make detectors for use with Lawrence's
cyclotrons. Cooksey continued to be a close associate of Lawrence and became associate director of the
Lawrence Radiation Laboratory of the
University of California at Berkeley. Donald Cooksey and his wife Milicent Sperry had a son, Donald Dows Cooksey (b. 1944), and a daughter, Helen Sperry Cooksey (b. 1947), who became a surgeon. ==References==