 |
| Leona Marshall Libby, 1946. |
There was also an intense race underway in laboratories far from the battlefields. Albert Einstein had escaped from Nazi Germany and warned President Franklin Roosevelt in 1939 that discoveries were being made and research conducted which, if completed, would lead to the creation of the most terrible weapon ever invented. The weapon would then be in the hands of whomever won that race, and the future of the entire world might very well hang on its outcome.
Roosevelt was determined that America must win that race; that such a weapon could not fall into the hands of Hitler and the Nazis. The United States embarked on a top secret crash program, called the Manhattan Project, to develop and construct the world’s first atomic bomb.
The American project would include some of the greatest scientific minds of the 20th Century. This chapter of the history of World War II includes names like Einstein, Teller, Oppenheimer and Fermi. But their story cannot be fully told without including another name: that of a young physicist from Illinois named Leona Marshall Libby.
Research for the Manhattan Project was conducted in labs and secret facilities all across America, most famously at Tennessee’s Oak Ridge National Laboratory and Washington’s Hanford Site. But key elements of the research were also conducted here in Illinois, most notably by Enrico Fermi’s team at the University of Chicago. This is where Leona Marshall Libby first crossed paths with the atomic bomb.
Born Leona Woods in LaGrange in 1919, Libby was nearing completion of her work toward a Ph.D. in spectroscopy at the University of Chicago, to go with the chemistry degree she had earned in 1938, at age 19. She looked forward to a career in physics. In fact, she had changed doctoral advisors after her first advisor suggested a woman had no future in the field of physics – he told her she would “starve to death.” Working instead with Dr. Robert Mulliken (who would win a Nobel Prize for chemistry in 1966), she studied spectroscopy and became an expert in vacuum technology, a skill which would prove vital to the work being done by the Manhattan Project.
She was hired as the youngest member of the team at the Chicago Metallurgical Laboratory, becoming the first woman chosen for the team working with Enrico Fermi in Chicago creating the world’s first nuclear reactor. The lab was charged with finding a way to produce plutonium for a nuclear chain reaction, the key element in the atomic bomb.
“My job was to use the expertise I already had to build boron tri-fluoride counters for detection of the neutron flux in the chain-reacting pile yet to be built,” she later explained, using the original term “pile” to describe what we now call a nuclear reactor. Her expertise was put to use in calibrating the equipment which would help the group of 49 scientists to determine the output of the reactor, known as CP-1. It was this team which on December 2, 1942, achieved the first controlled nuclear reaction.
While working there she met a fellow scientist named John Marshall and the two were married in the summer of 1943. Libby soon learned that she was pregnant, a fact which could have threatened her ability to keep working on the project if it became widely known. Trusting only her husband and Fermi with the secret, she determined to stay on the job. She took advantage of the lab’s unofficial uniform of baggy overalls with pockets stuffed with tools to conceal her pregnancy until just days before delivery. The couple’s son, Peter, was born in 1944. His mother was back in the lab a week later.
She cited her commitment to the research and the tremendous importance of the work as contributing to her decision. “If the Germans had got it before we did, I don’t know what would have happened to the world.”
Moving once again with the project, this time to Hanford, Washington, Libby characterized her job as “babysitting” the new plutonium reactor there. But her work was quite a bit more than that. It was her team which determined the cause of a September 1944 accident in the reactor, attributing it to xenon-135 poisoning which had caused the reactor to shut down after absorbing more neurons than it was capable of producing.
Meanwhile, the United States gained the upper hand in the race to build the bomb, helped along in part by a mistaken assumption the Germans made concerning one of the materials needed for building a reactor. It was an error which Libby and her colleagues on Fermi’s team had not made, and it was a critical difference in the race. Allied armies overwhelmed the Germans in Europe before their scientists could solve the problem. The United States exploded the first atomic bomb in July 1945 and dropped two of the devices on Japan the following month. The war ended days later.
“I certainly do recall how I felt when the atomic bombs were used,” she recalled later. “My brother-in-law was captain of the first minesweeper scheduled into Sasebo Harbor. My brother was a Marine, with a flamethrower on Okinawa. I’m sure these people would not have lasted in an invasion.”
After the war, Libby went to work at the University of Chicago, continuing her work with Fermi on nuclear reactors and becoming a fellow at the Institute for Nuclear Studies. She later took her studies to Princeton where she teamed with J. Robert Oppenheimer, the “father of the atomic bomb,” and then the RAND Corporation, which worked on issues of nuclear proliferation and strategy throughout the Cold War. She went into teaching and became a physics professor at New York University in 1962, and also did important research in the fields of high energy physics and stellar spectroscopy, as well as studying radioactivity and its effect on the environment. One of her breakthroughs in this field led to the discovery of decaying isotopes in tree rings as a method of studying natural history.
She re-married in 1966 to Dr. Willard Libby. Over the next couple of decades, she published hundreds of scientific articles and papers, and even a memoir of the Manhattan Project in 1979 titled The Uranium People. Late in life she taught environmental science and nuclear engineering at UCLA, helping train future scientists in ways to fight pollution. Leona Marshall Libby died November 10, 1986.
“She said there were people who tried to discourage her and she just sort of outworked and outshone some of the best of them,” her son John Marshall III told the Los Angeles Times after her death.
