Ernest Lawrence: Wikis

Advertisements
  
  

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Encyclopedia

From Wikipedia, the free encyclopedia

Ernest Lawrence

Ernest O. Lawrence
Born August 8, 1901(1901-08-08)
Canton, South Dakota
Died August 27, 1958 (aged 57)
Palo Alto, California
Residence United States
Nationality American
Fields Physics
Institutions Yale University
University of California
Alma mater University of South Dakota
University of Minnesota
Yale University
Doctoral advisor W.F.G. Swann
Doctoral students Edwin McMillan
Chien-Shiung Wu
Known for The invention of the cyclotron atom-smasher
elementary particle physics
The Manhattan Project
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 atom-smasher beginning in 1929, and his later work in uranium-isotope separation for the Manhattan Project. Lawrence had a long career at the University of California, where he became a Professor of Physics. In 1939, Lawrence was awarded the Nobel Prize in Physics for his work in inventing the cyclotron and developing its applications. Chemical element number 103 is named "lawrencium" in Lawrence's honor. He was also the first recipient of the Sylvanus Thayer Award.[1] His brother John H. Lawrence was known for pioneering in the field of nuclear medicine.

Contents

Early life

Born in Canton, South Dakota, Lawrence attended St. Olaf College in Minnesota, but he transferred to the University of South Dakota after his first year. Lawrence completed his bachelor's degree in 1922. He earned his master's degree in physics from the University of Minnesota in 1923. Next, Lawrence spent a year at the University of Chicago, and then he moved on to Yale University, where he completed his Ph.D. degree in physics in 1925, making him somewhat unusual in his field—a very promising young physical scientist who had received his entire education in the United States. These were years when study at one of the great science institutions of Europe was considered to be essential for anyone who truly wished to make a significant scientific progress. Lawrence remained at Yale University as a researcher, working in the photoelectric effect, and he became an assistant professor there in 1927.

In 1928, Lawrence was hired as an Associate Professor of Physics at the University of California, and two years later he became a full Professor, becoming the youngest Professor at the University of California. There, he was called the "Atom Smasher", and 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 that Laboratory's official Web site.

Robert Gordon Sproul was a member of the Bohemian Club, and he sponsored Lawrence's membership in 1932. Through this club, Lawrence met William H. Crocker, Edwin Pauley, and John Francis Neylan. They were influential men who helped him obtain money for his energetic nuclear particle investigations.[2]

The Developments of the Cyclotron

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.

Other scientists, including Leo Szilard, had both investigated similar concepts, though Lawrence is credited with developing it further and turning it into practice.[3]

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-electron volt protons spinning around (at about 1% the speed of light). 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 and the Manhattan Project

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 nuclear research, and it was Lawrence who first introduced J. Robert Oppenheimer into what would soon become the Manhattan Project. An early champion of the electromagnetic separation method to enrich uranium and increase its percentage of fissile U-235, Lawrence manufactured his magnetic calutrons — specialized forms of mass spectrometers — for the massive isotope separation plants in Oak Ridge, Tennessee. Lawrence's secretary, Helen Griggs married the future Nobel Prize in Chemistry winner, Glenn T. Seaborg, in 1942, as the three of them made their way to work on the Manhattan Project in Chicago, Illinois.

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 that Lawrence travel to Geneva, Switzerland, to help 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 decided to go, but he became ill while in Geneva, and was rushed to the hospital at Stanford University. Lawrence died one 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 O. 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.

References

  1. ^ Information Office United States Military Academy West Point, New York (March 4, 1958). "Dr Ernest Orlando Lawrence". http://www.aogusma.org/aog/awards/TA/Thayer58.htm. Retrieved 2008-03-07.  
  2. ^ Brechin, Gray A. (1999). Imperial San Francisco: Urban Power, Earthly Ruin. Berkeley: University of California Press. p. 312. ISBN 0520215680.  
  3. ^ On Szilard and the cyclotron, see Richard Rhodes, The Making of the Atomic Bomb (New York: Simon & Schuster, 1986), 23.

External links

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

Advertisements

Simple English


Ernest Orlando Lawrence (1901 –1958) was an American physicist. he was born on the 8th October, 1901 in South Dakota and he died in 1958. He helped invent the nuclear bomb during World War II and he won the Nobel prize for physics in 1939. His work was important in the science of nuclear physics. He worked out a way of measuring the mass of an electron, part of an atom.


Advertisements






Got something to say? Make a comment.
Your name
Your email address
Message