Historical Encyclopedia of Atomic Energy

Abelson, Philip Hauge

Philip Abelson (1913-) was an American physicist active in the separation of isotopes of uranium for the Manhattan Project. He was born on April 27, 1913, in Tacoma, Washington. His undergraduate degree in chemistry was from Washington State University, Spokane, Washington. In 1939, Abelson received his Ph.D. in physics from the University of California at Berkeley. Although Abelson was working on experiments at the University of California that were leading him toward the discovery of nuclear fission, the Germans, under Otto Hahn, beat him by a few weeks. His entire professional career, apart from the war years, was spent at the Carnegie Institution in Washington, DC.

During World War II, Abelson worked for the Naval Research Laboratory in Washington, DC. On the eve of the war, he assisted Edwin McMillan in experiments at the Berkeley cyclotron that created neptunium. Next Abelson worked on the separation of isotopes of uranium for the U.S. Navy, beginning in 1941. Using the thermal diffusion process at the Philadelphia Navy Yard, he was able to isolate small amounts of uranium-235. The navy was interested in this process to generate atomic energy for future ship propulsion, especially submarines. This unexpected source of uranium-235 prompted General Leslie Groves, head of the Manhattan Project, on the recommendation of J. Robert Oppenheimer, to add Abelson's process to the mix of methods in order to acquire enough material for an atomic bomb. Because Abelson's research made it possible to consider isolating enough U-235 to make a bomb, a huge plant at Oak Ridge, Tennessee, was constructed to carry out this process.

After the war, Abelson returned to the Carnegie Institution. His research turned away from nuclear topics to biophysics projects. Abelson became

-1-