Walton, Ernest Thomas Sinton

▪ 1996

      Irish physicist (b. Oct. 6, 1903, Dungarvan, County Waterford, Ireland—d. June 25, 1995, Belfast, Northern Ireland), was corecipient, with Sir John Douglas Cockcroft of England, of the 1951 Nobel Prize for Physics for their fundamental work on "the transmutation of atomic nuclei by artificially accelerated atomic particles," work they accomplished by means of a primitive nuclear particle accelerator known as the Cockcroft-Walton generator. Walton, the son of a Methodist minister, studied mathematics and experimental science at Trinity College, Dublin, and nuclear physics at Trinity College, Cambridge, where he worked with Cockcroft in Lord Rutherford's Cavendish Laboratory. In April 1932 Walton and Cockcroft, using a device they had constructed from glass cylinders, vacuum tubes, and car batteries, shot a beam of protons into a target of lithium, splitting the lithium atom into two helium atoms. The news that Walton and Cockcroft had split the atom without the use of radioactive elements spread quickly, but by the time the results of their experiment were formally announced, they had split the nuclei of 15 different elements. In 1934 Walton returned to Trinity College, Dublin, as a fellow in the physics department. He was appointed Erasmus Smith's professor of natural and experimental philosophy in 1946, and he retired in 1974.

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▪ Irish physicist

born Oct. 6, 1903, Dungarvan, County Waterford, Ire.

died June 25, 1995, Belfast, N.Ire.

      Irish physicist, corecipient, with Sir John Douglas Cockcroft (Cockcroft, Sir John Douglas) of England, of the 1951 Nobel Prize for Physics for the development of the first nuclear particle accelerator, known as the Cockcroft-Walton generator.

      After studying at the Methodist College, Belfast, and graduating in mathematics and experimental science from Trinity College, Dublin (1926), Walton went in 1927 to Trinity College, Cambridge, where he was to work with Cockcroft in the Cavendish Laboratory under Lord Rutherford until 1934. In 1928 he attempted two methods of high-energy particle acceleration. Both failed, mainly because the available power sources could not generate the necessary energies, but his methods were later developed and used in the betatron and the linear accelerator. Then in 1929 Cockcroft and Walton devised an accelerator that generated large numbers of particles at lower energies. With this device in 1932 they disintegrated lithium nuclei with protons, the first artificial nuclear reaction not utilizing radioactive substances.

      After gaining his Ph.D. at Cambridge, Walton returned to Trinity College, Dublin, in 1934, where he remained as a fellow for the next 40 years and a fellow emeritus thereafter. He was Erasmus Smith professor of natural and experimental philosophy from 1946 to 1974 and chairman of the School of Cosmic Physics at the Dublin Institute for Advanced Studies after 1952.

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