Phillips earned a master's degree in physics from Battle Creek College in Michigan in 1928 and a doctorate in physics (PhD) at the University of California, Berkeley in 1933. She was one of the first doctoral students of J. Robert Oppenheimer, who later became scientific head of the Manhattan Project, the Allied effort to develop the Atomic bomb. In 1935, Oppenheimer and Phillips published their description of the Oppenheimer–Phillips process, which explained the behavior of accelerated nuclei of radioactive, "heavy hydrogen " atoms. The Oppenheimer–Phillips effect was one of the earliest contributions to nuclear physics.