Ernest Lawrence

Ernest Lawrence
Ernest O. Lawrence
Ernest O. Lawrence
Born August 8, 1901(1901-08-08)
Canton, South Dakota, United States
Died August 27, 1958 (aged 57)
Palo Alto, California, United States
Residence United States
Nationality American
Fields Physics
Institutions Yale University
University of California, Berkeley
Alma mater University of South Dakota
University of Minnesota
Yale University
Doctoral advisor W. F. G. Swann
Doctoral students Edwin McMillan
Known for invention of the cyclotron
Notable awards Nobel Prize in Physics 1939

Ernest Orlando Lawrence (August 8, 1901 – August 27, 1958) was an American physicist and Nobel Laureate, known for his invention, utilization, and improvement of the cyclotron beginning in 1929, and his later work in uranium-isotope separation in the Manhattan Project. He had a long career at the University of California, Berkeley where he was a professor of physics. In 1939, Lawrence was awarded the Nobel Prize in Physics for his work on the cyclotron and its applications (however, Sándor Gaál first invented the device, but could not publish it, so the offical credit goes to Ernest Lawrence). Chemical element number 103 is named "lawrencium" in his honor. He was also the first recipient of the Sylvanus Thayer Award.[1] His brother John H. Lawrence is known for pioneering the field of nuclear medicine.

Contents

Early life

Born in Canton, South Dakota, Lawrence attended St. Olaf College in Minnesota, but transferred to the University of South Dakota after his first year. He earned his bachelor's degree in 1922. He received his Master's Degree in Physics from the University of Minnesota in 1923. He spent a year at the University of Chicago, and received his Ph.D. in physics at Yale University in 1925, making him somewhat unusual in his field -- a very promising young scientist who had received his entire education in the United States, in a day when study at one of the great science institutions of Europe was considered essential for someone who truly wished to make a significant contribution. He remained at Yale as a researcher on the photoelectric effect, becoming an assistant professor in 1927.

In 1928 he was appointed Associate Professor of Physics at the University of California, Berkeley, and two years later he became a full Professor, being the youngest at Berkeley. There, he was called the "Atom Smasher,"; the man who "held the key" to atomic energy. "He wanted to do 'big physics,' the kind of work that could only be done on a large scale with a lot of people involved," said Herbert York, the first director of the Lawrence Livermore laboratory, as quoted on the lab's official Web site.

Cyclotron

The very first cyclotron was designed by Sándor Gaál, but by misfortune could not publish it, so the offical credit goes to Ernest Lawrence.

The invention that brought Lawrence to international fame started out as a sketch on a scrap of paper. While sitting in the library one evening, Lawrence glanced over a journal article and was intrigued by one of the diagrams. The idea was to produce very high-energy particles required for atomic disintegration by means of a succession of very small "pushes." The device as depicted however, was laid out in a straight line using increasingly longer electrodes. Lawrence saw that such an accelerator would soon become too long and unwieldy for his university laboratory. In pondering a way to make the accelerator more compact, Lawrence decided to set a circular accelerating chamber between the poles of an electromagnet. The magnetic field would hold the charged protons in a spiral path as they were accelerated between just two semicircular electrodes connected to an alternating potential. After a hundred turns or so, the protons would impact the target as a beam of high-energy particles. Lawrence excitedly told his colleagues that he had discovered a method for obtaining particles of very high energy without the use of any high voltage.

Diagram of cyclotron operation from Lawrence's 1934 patent.

The first model of Lawrence's cyclotron was made out of brass, wire, and sealing wax and was only four inches in diameter--it could literally be held in one hand. It probably cost $25 in all. And it worked: When Lawrence applied 2,000 volts of electricity to his makeshift cyclotron on January 2, 1931, he got 80,000-volt protons spinning around. Through his increasingly larger machines, Lawrence was able to provide the crucial equipment needed for experiments in high energy physics. Around this device, Lawrence built up his Radiation Laboratory, which would become the world's foremost laboratory for the new field of nuclear physics research in the 1930s. He received a patent for the cyclotron in 1934, which he assigned to the Research Corporation. In 1936 the Radiation Laboratory became an official department of the University of California with Lawrence formally appointed its Director. He served in that capacity until his death.

In November 1939, Lawrence was awarded the Nobel Prize in Physics for his work on the cyclotron and its applications. Not only was he the first at Berkeley to become a Nobel Laureate, he was also the first ever to be so honored while at a state-supported university. The award ceremony was held on February 29, 1940 in Berkeley, California due to the war, in the auditorium of Wheeler Hall on the campus of the university with Lawrence receiving his medal from Carl E. Wallerstedt, Sweden's Consul General in San Francisco.

World War II

Giant calutron plants developed at Lawrence's laboratory were used at Site X during World War II to purify uranium for use in the first atomic bomb.

During World War II, Lawrence eagerly helped to ramp up the American investigation of the possibility of a weapon utilizing nuclear fission. His Rad Lab became one of the major centers for wartime atomic research, and it was Lawrence who first introduced J. Robert Oppenheimer into what would become the Manhattan Project. It was at Lawrence's personal recommendation that General Leslie R. Groves appointed Oppenheimer Director of the New Mexico laboratory that would produce the first atomic bombs. An early champion of the electromagnetic separation method to enrich uranium, Lawrence manufactured his calutrons — specialized forms of mass spectrometers — for the massive separation plants at Oak Ridge, Tennessee. His secretary, Helen Griggs married future Nobel chemistry laureate Glenn T. Seaborg in 1942 as they made their way to work on the Manhattan Project in Chicago.

Post-war Career and Legacy

After the war, Lawrence campaigned extensively for government sponsorship of large scientific programs. Lawrence was a forceful advocate of "Big Science" with its requirements for big machines and big money.

For his service to his country, Lawrence received the Enrico Fermi Award from the U.S. Atomic Energy Commission in 1957, and was the first recipient of the prestigious Sylvanus Thayer Award by the United States Military Academy in 1958.

In July 1958, President Eisenhower requested Lawrence travel to Geneva, Switzerland, to negotiate a proposed treaty with the Soviet Union to ban nuclear weapons testing. Despite suffering from a serious flare-up of his chronic colitis, Lawrence participated, but became ill while in Geneva and was rushed to the hospital at Stanford. He died a month later in Palo Alto, California, at the age of 57.

Just 23 days after his death, the Regents of the University of California voted to rename the Lawrence Livermore and Lawrence Berkeley Laboratories after him. The Ernest Orlando Lawrence Award was established in his memory in 1959. Chemical element number 103, discovered at LBNL in 1961, is named "lawrencium" in his honor. In 1968 the Lawrence Hall of Science public science education center was established in honor of Ernest Lawrence, who had been throughout his career a passionate advocate of encouraging public interest in science, particularly among schoolchildren. The museum features a permanent exhibit devoted to Lawrence's life.

On March 7, 2007 Lawrence's Nobel Prize gold medal was briefly stolen from a low-security glass cabinet in the museum.[2] The alleged perpetrator was a 22-year-old local student who worked in the building. He reportedly used a copied key to remove the medal as a prank. The medal was returned but will not be presented to the public until May 2008, when a new armored vault will be constructed for the exhibit.

References

  1. Information Office United States Military Academy West Point, New York (March 4, 1958). "Dr Ernest Orlando Lawrence". Retrieved on 2008-03-07.
  2. Gilmore, Janet (March 7, 2007). "Nobel Prize medal stolen from Lawrence Hall of Science is found, student arrested". UC Berkeley News. Retrieved on 2008-03-07.

External links

Preceded by
none
Sylvanus Thayer Award
1958
Succeeded by
John Foster Dulles