Known as the youngest physics professor at the University of California at Berkeley, Ernest Orlando Lawrence played a major role in the development of nuclear physics. From 1936 until his death he was director of the Radiation Laboratory at Berkeley, where he invented the cyclotron , a device that accelerates the speed of nuclear particles. The invention of the cyclotron inaugurated a new era in the study of nuclear physics, and for this achievement he was awarded the 1939 Nobel Prize in physics. At Lawrence's laboratory several radioactive isotopes were discovered; one of these was plutonium, an element essential to the development of the atomic bomb. Lawrence played an active role in the research on nuclear weapons both during and after World War II, and he remained a strong advocate of increasing America's nuclear arsenal.
Lawrence was born in Canton, South Dakota, on August 8, 1901, the eldest son of Carl Gustav Lawrence and Gunda Jacobson Lawrence. Both parents were of Norwegian ancestry; his mother was a teacher, and his father was a state superintendent of public education who then became president of a teacher's college. Lawrence completed public school in South Dakota at age 16; he began college at Saint Olaf's in Minnesota and then transferred to the University of South Dakota, from which he graduated with a B.S. in 1922. His gift for physics had become apparent, and he went on to earn a master's degree in 1923 at the University of Minnesota. He then followed his physics professor, W. F. G. Swann, first to the University of Chicago and then to Yale, where in 1925 Lawrence completed his doctorate. His dissertation was on the photoelectric effect , a phenomenon that occurs when certain electrons give off lightenergy as they change their position around the nucleus of an atom. By this time he had met such notable physicists as Albert Michelson and Niels Bohr and had gained a reputation for being an innovative experimenter.
Lawrence left Yale in 1928 for a job at the University of California at Berkeley, which was then a little-known state school. But the seeds for growth in the field of nuclear physics were sown with the hiring of Lawrence and his contemporary, J. Robert Oppenheimer. Berkeley was soon to be a center for nuclear research equal to any other in the world. In 1930, a mere two years later, Lawrence became a full professor at just 29 years of age. While at Yale, Lawrence had met his future wife, Mary Kimberly Blumer, who was the daughter of the dean of Yale's medical faculty. Molly, as she was called, was just 16 at the time. They were married in 1932, and she joined him in California. They would have two sons and four daughters.
Develops the Cyclotron
At Berkeley, Lawrence became interested in the nucleus, or center, of atoms. In particular, he was curious about what kinds of reactions would occur if protons, the positively charged particles in the nucleus, were given high energy levels. He had read about a Norwegian engineer who had built a device that accelerated nuclei in a straight line, but it had failed to impart enough power to cause nuclear reactions. With graduate students Niels E. Edlefsen and M. Stanley Livingston, Lawrence developed a circular, rather than linear, accelerator. The particle accelerator had the shape of a flat circular can cut in two. When particles such as protons were placed in the center of the can, a magnetic field forced them to travel in a circular path. Each time a particle went by, the magnetic field pushed it again. All of these small pushes increased the speed of the particle as it spiraled toward the rim of the can. When it approached the rim, the particle was made to hit a target--a nucleus. The result would be to disintegrate or "smash" the nucleus. Lawrence called the device a cyclotron and he and his team began to improve on it. They were fortunate enough to convince the Federal Telegraph Company to donate a huge 80-ton magnet that was no longer in use. With this magnet, and a bigger cyclotron chamber, Lawrence could impart a great deal of energy onto particles, measured in millions of electron volts.
The cyclotron ushered in a new era of experimentation in high-energy physics. In 1932, Lawrence and his team were able to disintegrate a lithium nucleus. As they smashed other nuclei, they were able to measure how much energy is needed to bind the nucleus of an atom together. In other experiments they bombarded other elements to obtain radioactive isotopes of carbon, iodine, and uranium. With his younger brother John Lawrence, who was also at Berkeley, Lawrence looked for medical uses for radioisotopes; one development was using them as tracers to study metabolism, an application that is still important today. In 1936, at age 35, Lawrence became the director of the Radiation Laboratory at Berkeley. In 1939, with the importance of the cyclotron proven, he received the Nobel Prize. He had already been the recipient of the Comstock Prize of the National Academy of Sciences and the Royal Society's Hughes Medal.
Participates in the Development of the Atomic Bomb
During World War II, the Radiation Laboratory, with Lawrence at the helm, played an important role in developing the atomic bomb . Urged on by German refugees who feared that the Nazis might produce an atomic weapon first, his laboratory worked to obtain the most useful materials for nuclear fission. When nuclear fission occurs, the nucleus of some radioactive elements disintegrates, releasing a great deal of energy. Research was done at Berkeley to find a way to separate uranium, and the technique was then used on a larger scale at the laboratory at Oak Ridge, Tennessee, which provided the uranium 235 for the atomic bomb that was eventually dropped on Hiroshima. While Lawrence remained at the Radiation Laboratory, J. Robert Oppenheimer went to direct the laboratory at Los Alamos, New Mexico, where the first bomb was made.
After the dropping of two fission bombs on Hiroshima and Nagasaki, resulting in destruction and loss of life never seen before in human history, there was a division in the ranks of the world's nuclear physicists. In the postwar era, Oppenheimer and others became convinced that the development of further nuclear weapons should cease in the interest of humanity. But Lawrence believed in continuing this work. He argued that it was in the interest of the United States to build even more powerful weapons, such as the hydrogen or thermonuclear bomb. The rift between these two men came to a head when Oppenheimer appeared before a Congressional hearing and subsequently lost his security clearance. The opinion of the government and the public at the time supported Lawrence's advocacy of nuclear buildup.
Lawrence and Hungarian-born physicist Edward Teller founded a second radiation laboratory in Livermore, California, for research on nuclear weapons. Bigger and better accelerators were created that could boost nuclear particles with energy measured in billions of electron volts; thus was born a powerful accelerator known as the bevatron. Lawrence's visions for physics laboratories on a grand scale set the stage for the particle accelerators built in the suburbs of New York and Chicago--Brookhaven National Laboratory on Long Island and the Fermi National Accelerator Laboratory in Geneva, Illinois. He also influenced the creation of an accelerator at the European Center for Nuclear Research (CERN) in Switzerland. Each laboratory was set up with an international team of physicists, in much the same way the Radiation Laboratory had been.
During the 1950s, Lawrence oversaw operations in the nuclear research laboratories he had helped to fashion. His original cyclotron had been superseded by newer and faster ones designed by other scientists, but he continued to show his inventiveness, both in nuclear physics and in applied physics. He even designed a novel type of color television picture tube. In 1957 he was awarded the Fermi Award, the highest honor in physics in the United States. Lawrence was also busy as a government consultant on nuclear-energy issues for the Eisenhower administration. In the summer of 1958 he attended a conference in Geneva on the possibility of detecting violations of nuclear test agreements, but, ill and weary from recurrent ulcerative colitis, he flew home for an operation. He did not survive and died on August 27, 1958.
In 1961, the transuranium element 103 was discovered at Berkeley and was named lawrencium in his honor. The Lawrence Hall of Science at the university is a museum and research center dedicated to improving science education. The Radiation Laboratory is now known as the Lawrence Berkeley Laboratory, and the facilities in Livermore, California, are now called the Lawrence Livermore Laboratory.
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