Staff Biographies

Elizabeth Graves

Elizabeth "Diz" Riddle Graves was one of several young PhD physicists to join the ranks of the illustrious group of scientists working at the University of Chicago's so-called Metallurgical or Met Lab in the war years of 1942 and 1943. Because her dissertation work had involved neutron-scattering experiments, her skills were immediately transferable to the Chicago atomic project. Soon after she moved on to the Los Alamos project to work on the neutron reflector that would surround the core of the atomic bomb.

Contributing Her Unique Expertise to Atomic Projects

As noted in Their Day in the Sun: Women of the Manhattan Project:

"No one had yet measured the effectiveness of various materials in scattering high-energy neutrons, but Elizabeth Graves was one of the few physicists in the country with experience in fast-neutron scattering and in using the Cockcroft-Walton accelerator, one of which had been brought to Los Alamos from the University of Illinois. "

Her path from Chicago to Los Alamos was not direct, however. Graves's husband, Al, whom she had married while they were physics graduate students at Chicago, was hired by the University of Texas in 1944. When Elizabeth Graves tried to join him there, the university's nepotism rules kept her from being hired, so she came instead to Los Alamos and contributed her expertise to the Manhattan Project.

Mixing family and professional responsibilities occupied Elizabeth Graves during her years at Los Alamos. She is said to have been wrapping up some of her experiments in her laboratory while clocking her contractions preceding the birth of her first child.

Fielding Radiation Concerns

In fact, personal concerns had also been a part of Elizabeth and Al Graves's assignment to monitor radiation from the Trinity test site on July 16,1945. Because she was seven-months pregnant at the time of the Trinity test, Elizabeth and Al requested that they do their monitoring from a distance, so that their unborn child would not be exposed to any danger.

Though she experienced no problems with the birth of her child, radiation concerns confronted the Graves less than a year later when a critical-assembly test in which Al Graves participated went terribly awry. In his book, The Great American Bomb Machine, Roger Rapoport describes this frightening event:

With a tinge of nostalgia, [Manhattan Project physicist] Louis Slotin performed his critical-assembly test one last time, on May 21, 1946, for the edification of his successor, Al Graves, and six other men.... Slotin, who had conducted this test 40 times, approached this final exercise with his usual confidence. The slim, serious scientist pushed the pieces toward one another as usual, but suddenly he slipped, and the room filled with a blue ionization glow. The Geiger counter chattered, Slotin lunged, and flung the hemispheres apart....
Seven men charged out of the room, their lives saved by Slotin, who knew that he had taken a fatal dose of radiation. His first concern was Graves, who had been at his shoulder. Would he survive? He put the computation to Graves's wife Elizabeth, without telling her what happened. Mrs. Graves believed herself a stoic... But she froze when she learned who the subject of her calculation was.

Though her husband Al did survive the accident, the radiation caused him to develop several symptoms of neutron exposure. The incident, however, had an additional impact on Elizabeth Graves's career.

Turning Down an Appointment to the AEC
Shortly after the accident, the White House requested that she serve as one of five commissioners of the Atomic Energy Commission, established by the Atomic Energy Act of 1946. These commissioners were appointed by the President and confirmed by the U.S. Senate.

Because of her husband's condition, she turned down that very significant offer and stayed in Los Alamos. There she focused on research related to the measurement of cross sections for the interaction of fast neutrons with materials.

Though it was unusual to have a female group leader at Los Alamos even in the postwar years, Elizabeth Graves held that position from 1950 until her retirement in 1972. During those years she was a first author or coauthor of numerous articles and reports on such topics as neutron interactions, low-voltage neutron sources, and neutron-survey instrumentation. Her earliest reports in 1945 through 1947 focused on bomb-device technology and information on the Trinity test.

Paving a Path for Women Scientists at Los Alamos
Having turned down the opportunity to serve on the AEC, Graves avoided the mixed blessing of frequent travel to Washington, D.C. Instead she extended her scientific research and achievements over thirty years after the Trinity test.

In doing so she helped ensure the place of women scientists in the history of the national laboratories. She also joined a line of experimental physicists who came to Los Alamos, fell in love with the mountains, and chose to stay to raise her family in the former "secret city."