M. Stanley Livingston

Part I, History of the cyclotron

The principle of the magnetic resonance accelerator, now known as the cyclotron, was proposed by Professor Ernest O. Lawrence of the University of California in 1930, in a short article in Science by Lawrence and N. E. Edlefsen. It was suggested by the experiment of Wideroe in 1928, in which ions of Na and K were accelerated to twice the applied voltage while traversing two tubular electrodes in line between which an oscillatory electric field was applied—an elementary linear accelerator. In 1953 Professor Lawrence described to the writer the origin of the idea, as he then remembered it.

Early Development of Particle Accelerators

Professor Ernest O. Lawrence of the University of California conceived the idea of the cyclotron in 1929 and reported the principle in Science in 1930. The first successful experimental demonstration of cyclotron resonance was by Livingston in a Doctorate thesis completed in April, 1931, using a 4-in. pole magnet and producing H2+ ions of 80 000 ev energy. By late 1931 Lawrence and Livingston completed an 11-in. cyclotron which produced H+ ions of 1.2 Mev, and which was used with others in the laboratory for disintegration experiments. By late 1932 the “27-in.” cyclotron was completed and was in service for research experiments; the energy and intensity were steadily increased during 1933 and 1934 and both H2+ and D+ ions of up to 5 Mev energy became available. During these early years many young scientists joined the group to do research on disintegration reactions, neutron properties, and induced radioactivity, under the stimulating leadership of Professor Lawrence.

Employment problems ofyoung physicists

Information on the present attitudes of young scientists toward their prospective employment is useful in assessing the effects of graduate training, in evaluating the motivations of students, in aiding placement offices to find suitable jobs for graduates, and in many other ways. The increasing demand for scientists in our growing industrial system and in government defense laboratories requires accurate estimates of the supply of young scientists and of how they are being assimilated. Considerable evidence has been presented to show that the numbers now being trained are insuffident to meet future needs. A new problem has arisen in recent years, concerning the security status of scientists. It is of interest to know, for example, whether the unpleasant publicity given to several prominent security clearance cases has had a significant effect on the willingness of young Scientists to accept employment which requires Security clearence.