LIVINGSTON, MILTON STANLEY

(b. Broadhead, Wisconsin, 25 May 1905; d. Santa Fe, New Mexico, 25 August 1986),

nuclear physics, accelerator design and construction, science administration.

Livingston pioneered the development of particle accelerators. He was the principal collaborator of Ernest O. Lawrence, inventor of the cyclotron, during the first four years of its development, and a codiscoverer of the strong focusing principle essential to synchrotrons. Livingston was also an administrator for several key accelerator programs: first head of the Accelerator Project at Brookhaven National Laboratory, director of the Cambridge Electron Accelerator, and associate director of the National Accelerator Laboratory (later known as Fermilab).

Early Years . M. Stanley Livingston was born in 1905, the son of the minister of a small church in Broadhead, Wisconsin. When he was five, his father moved the family to southern California to take up the more promising career of schoolteacher, and also bought a ranch with an orange grove. Livingston later attributed his mechanical interests and abilities to the fact that it was his job to repair and maintain the farm tools and instruments, including tractors and trucks. His mother died when he was twelve, and his father remarried.

Livingston graduated from high school in 1921, having studied chemistry but not physics. He attended the nearby Pomona College and initially majored in chemistry—for, as he once explained in a videotaped interview in 1982, World War I had made chemistry the science to study just as World War II made physics the science. When Livingston left the farm to live on campus, his roommate was a physics major named Victor Neher. Livingston was losing interest in chemistry, and Neher fascinated Livingston with his tales as a lab assistant. In his senior year, Livingston took course overloads to allow him

to major in physics and chemistry. After his graduation in 1926, his physics professor, Roland R. Tileston, secured him a position as an instructor at Dartmouth College, where Tileston had connections. Livingston received an MA from Dartmouth in 1928, and stayed for another year as an instructor.

Lawrence and Cyclotrons . In 1929 Livingston obtained a fellowship to enter the University of California at Berkeley as a graduate student in physics. His MA and his own inventiveness gave him a head start over his classmates, and by the end of his first year—summer 1930—he had completed his course work, passed his qualifying exams, and asked several faculty members for ideas regarding thesis topics. The most intriguing suggestion came from Lawrence, Livingston’s instructor in the electricity and magnetism course: to look for the resonance of hydrogen ions, moving in a magnetic field, excited by an alternating electric current operating at radio frequencies. Not only was the topic exciting but so was Lawrence, an intense and driven experimenter who exuded confidence and ambition, Livingston once said, “gave everyone a feeling of enthusiasm and confidence.”

Lawrence, who had arrived at Berkeley in 1928, had seen a paper by Rolf Wideröe outlining a way to accelerate charged particles, and decided to fashion his own version. Lawrence had a graduating student, Niels Edlefsen, construct a primitive device, but the results were inconclusive. When Edlefsen received his degree in 1930 and left the laboratory, Lawrence sought another grad student—and along came Livingston. Livingston discovered that other faculty members had serious doubts about the idea, pointing out that the slightest perturbation would send the particles spiraling out of a flat plane and thus be lost. But Lawrence rekindled his enthusiasm, and Livingston took on the project.

Livingston rebuilt the device virtually from scratch, taking advantage of the close fraternity of other students working on their thesis projects and with the supervision of Lawrence, who dropped in almost every day to check on progress. The device might be described as in the form of a circular metal sandwich. The middle layer consisted of a vacuum chamber, and inside Livingston put a hollow D-shaped electrode. This chamber was placed between the cylindrical poles of a 4-inch (10.16-centimeter) electromagnet. The magnet would cause charged particles released in the center of the chamber to run in circular orbits, entering and leaving the D on each traversal of the circle. The D would be charged by an alternating radio-frequency excitation; inside the D was a field-free region. The particles would be alternately attracted and repelled by the D, gaining a slight amount of energy each time they entered and left it. The radius of the particle orbits would slowly increase, and eventually the particles would leave the chamber via a beam port. Such devices came to be called cyclotrons (see Figure 1).

Lawrence had realized the significance of resonance: that the excited particles would stay in step at the same frequency regardless of how fast they were traveling and thus how big their orbits grew—and therefore that repeated application of a small voltage V would result in a large total energy E (E = NeV, where N is the number of times the particle entered and left the D). Particles of mass M and charge e would revolve with frequency ω that was independent of the energy of the particles as they increased in speed, meaning that a constant frequency

applied to the D would continue to accelerate the particles (ω = eB/Mc, where B is the magnetic field and c is the velocity of light).

Livingston began work in summer 1930, and shortly discovered that Edlefsen had not detected resonance but another kind of acceleration effect. In November Livingston detected resonance for what was almost certainly the first time. Livingston then borrowed a bigger magnet, and in January 1931 used it and a thousand electron volt (KeV) voltage to accelerate hydrogen ions (H₂⁺) to 80 KeV. That result excited Lawrence and sent him, Livingston once recalled, “off to the races,” on a decade-long quest, successful even during the Depression, for ever-larger funding and support to build ever-bigger cyclotrons.

Then Lawrence forced Livingston to interrupt his work and finish his PhD requirements. Lawrence needed Livingston to have a PhD, for he had secured Livingston an instructorship, contingent on the PhD, which would enable Livingston to remain at Berkeley and continue constructing cyclotrons. Livingston wrote up and submitted his work in two weeks, but Lawrence forbade him to study for the orals, saying there was too much to do and he could brush up on nuclear physics later. In April 1931, despite being less prepared on nuclear physics—his forte lay in his mechanical abilities—Livingston took and passed the exam.

By this time, Lawrence had received a $1,000 grant from the National Research Council to build a cyclotron with an 11-inch (28-centimeter) magnet. Livingston set to work, this time using a pair of Ds with a small gap between them (see Figure 2). On 9 January 1932, the device passed an important milestone, becoming the first accelerator to exceed a million electron volts (MeV). Years later Livingston recalled: “As the galvanometer spot swung across the scale, indicating that protons of 1-MeV energy were reaching the collector, Lawrence literally danced around the room with glee. The news quickly spread through the Berkeley laboratory, and we were busy all that day demonstrating million-volt protons to eager viewers” (1969, p. 29). On 20 February 1932, they mailed their first publication to Physical Review, announcing that they had reached 1.2 million volts. In the early twenty-first century the machine is in the Science Museum in South Kensington, London.

A few months later, John Cockcroft and Ernest Walton of the Cavendish Laboratory in England announced that that they had used a different type of high-voltage acceleration device they had been developing to disintegrate nuclei. That reminded Lawrence and Livingston that they had rivals as accelerator builders, and of the need to pay attention to nuclear physics applications. Lawrence began to push his assistant even harder, with Livingston working until midnight most nights, including weekends and holidays. Lawrence and Livingston built ever-larger cyclotrons, the next being a device with 27.5-inch (69.85-centimeter) pole faces in the summer of 1932. It reached 5 MeV. They began nuclear experimentation with the aid of their colleague Gilbert Newton Lewis, who supplied deuterium (a hydrogen isotope that contains both a proton and a neutron), an effective projectile.

Somehow Livingston found time to meet and marry Lois Robinson, with whom he had two children, Diane (b. 1935) and Stephen (b. 1943).

During his four years at Berkeley, Livingston was the “mechanically minded person who could make these things happen,” he once said (AIP interview, 1967, p. 22), while Lawrence provided the funding, support, contacts, and drive. “Lawrence made waves in science,” Livingston recalled. “He made such big waves that we all got thrown up to the top. I coasted down the front side of that wave for the rest of my career, using what I had acquired in the way of a reputation, experience, and contacts” (Video interview, 1982, cited in Crease, 1999).

Yet it was Livingston who was responsible for two improvements essential to the success of cyclotrons, one having to do with the electric focusing, the other with the magnetic focusing. The first cyclotrons had been built with wires strung across the opening of the D to create an electric plane thought essential to focus the particles; Livingston discovered that the wires were not only unnecessary, because of an unsuspected focusing effect, but that their removal boosted the intensity. Livingston’s second improvement was to use shims to create a “fringing field,” or slightly bowed shape to the magnetic field, which focused the particles in midplane.

The Berkeley cyclotron team, however, made a slow start on nuclear physics experimentation, and became involved in an embarrassing episode involving the disintegration of deuterium in which target contamination led them to misjudge the mass of the neutron. And one day in 1934, Lawrence came running into the lab waving a copy of the French journal Comptes Rendus, containing an article by Frédéric Joliot-Curie and Irène Joliot-Curie announcing the discovery of induced radioactivity, a phenomenon that the Berkeley crew easily could have observed earlier. Half an hour later, they were observing it as well.

But the cyclotron soon put Berkeley on the map as a center for nuclear physics. It was the beginning of the era when accelerators were the key to nuclear physics—except in slow neutron physics of the sort Enrico Fermi was doing—and the ability to make discoveries was a function of the size of the accelerator. “Nuclear physics just blew wide open,” Livingston once said. “Here was this machine, where essentially everything you touched made a publishable paper. … The papers just poured out of that lab” (Video interview, 1982, cited in Crease, 1999). The historians John Heilbron and Robert Seidel have written, “The technical achievement was mainly Livingston’s; the inspiration, push, and above all, the vision of future greatness, were Lawrence’s.”

Cornell and MIT . But Livingston was increasingly unhappy at Berkeley. He felt more and more in Lawrence’s shadow, and chafed at the way Lawrence somehow retained all the credit. Lawrence’s 1932 patent application for the cyclotron did not mention Livingston (though this seems to have been thoughtless rather than intentional, as Lawrence was in a rush to beat another applicant) and when Lawrence was awarded the Nobel Prize, in 1939, it was “for the invention and development of the cyclotron.” In 1933 Livingston had been offered a job elsewhere, but Lawrence persuaded him to turn it down. In 1934 Livingston received an offer from Cornell, and this time, he accepted.

Cornell was an increasingly influential center for nuclear research thanks to the presence of physicists such as Robert Bacher and Hans Bethe. Livingston was attracted by the prospect of being able to build cyclotrons himself, and by the opportunity to catch up on nuclear physics. At Cornell, with $800 and half a dozen graduate students, he built the first cyclotron outside Berkeley, a 16-inch (41 centimeter) 2 MeV proton machine. He also collaborated with Bethe on one of Bethe’s three seminal articles in Reviews of Modern Physics (published in 1936 and 1937) that surveyed the field of nuclear physics and that scientists in the field affectionately referred to as “Bethe’s Bible.”

In 1938 Livingston moved to the Massachusetts Institute of Technology (MIT). This move was motivated not by unhappiness but by opportunity. The physicist Robley Evans was about to build a large cyclotron financed by the Markle Medical Foundation, and used the project to lure Livingston. There he built, for $60,000, a 42-inch (107-centimeter) 12-MeV cyclotron, which came into operation in 1940.

During World War II, when some of Livingston’s colleagues moved to the MIT Radiation Laboratory—the RadLab—to work on radar technology, and others went to various outposts of the Manhattan Project, Livingston remained for the first part of the war at his cyclotron, which was performing war duty by producing radioisotopes. In 1944 Livingston was recruited by his MIT colleague Philip Morse to work at the Office of Scientific Research and Development (OSRD) at Morse’s underwater sound laboratory in Washington, D.C.

Brookhaven and Synchrotrons . After the war in mid-1946, Morse was chosen by a consortium of nine northeast universities—MIT among them—to become head of Brookhaven National Laboratory (BNL), one of the first U.S. national laboratories. Morse convinced Livingston to take leave of MIT to head BNL’s accelerator program. Livingston was the obvious choice for his experience, ambition, and connections. He, in turn, saw it as the chance—finally—to create a wave of his own, thanks to the substantial government backing of the new lab. The initial plan was to build four accelerators: a van de Graaff for the low energies, a cyclotron for intermediate energies, a 240-inch (610-centimeter) offspring of the cyclotron called a synchrocyclotron for the high end, and a yet-tobe-designed accelerator for the future.

Synchrocyclotrons were a recent discovery, designed to overcome a limitation on cyclotrons. For there was a limit to the resonance principle, created by the fact that particles increase in mass as they approach the speed of light. This means that they take longer to complete an orbit, and thus they get out of phase with respect to the frequency of the voltage changes. In 1945 a way around this problem was announced by the Soviet physicist Vladimir Veksler and independently by the Berkeley physicist Ed McMillan. The idea involved decreasing the frequency of the voltage changes with the rise in energy of the particles to compensate for their increased energy and to keep the particles synchronous—hence the name “synchrocyclotron.” This idea not only extended the lifetime of cyclotrons, but also suggested a new kind of accelerator (called a synchrotron), in which the magnets surrounded the particle path like beads on a string.

Livingston was particularly interested in the synchrocyclotron, which would be able to reach 600–1000 MeV. This was an important region because pions, whose study was now important to nuclear physics, would be produced easily. It would not only be the world’s most powerful accelerator, but it would be the last hurrah of cyclotrons before they gave way to synchrotrons. But support for the project eroded when other BNL scientists embraced the idea of putting the lab’s resources into a synchrotron instead. Livingston was reluctant to abandon the synchrocyclotron and did not like the thought of placing all the lab’s high-energy funds in one project, gambling on an entirely new type of machine. But in April 1947 the laboratory decided to abandon the synchrocyclotron project to focus on a synchrotron. Though Livingston was initially furious, he gracefully overcame his objections and contributed to the design of what would become known as the Cosmotron. In fall 1948 he returned to MIT but continued to return to BNL as a summer visitor. And in that capacity he became involved in one of the most momentous breakthroughs in accelerator physics, the discovery of strong focusing.

The Cosmotron was completed in May 1952 and was the first accelerator to exceed a billion electron volts (1 GeV). Meanwhile, a new European accelerator laboratory was being set up outside Geneva, then known as the Conseil Européen pour la Recherche Nucléaire, now known as CERN. The European scientists planned to build a synchrotron, and a trio of CERN accelerator scientists— including Wideröe—was sent to BNL to examine the Cosmotron. In advance of their visit, Livingston organized a study group to brainstorm for ideas to give to the Europeans. One major drawback to the Cosmotron, for instance, was the fact that its magnets were C-shaped, meaning that the beam could be accessed from only one side. What, Livingston asked BNL accelerator designer Ernest Courant, if the magnets alternated in sectors, with some pointing in and some out?

Courant’s immediate response was to cite the conventional wisdom that this would disrupt orbital stability, but promised to look into it. When he did, he was astonished to arrive at the opposite conclusion—that alternating the magnets would improve focusing and orbital stability. The method turned out to have an antecedent, called the butterfly cyclotron, and it had also been discovered previously by a Greek engineer, Nicholas Christofilos, whose work had been overlooked. But by the time the CERN team arrived at BNL in August, Livingston, Courant, and the third member of the group, Hartland Snyder, realized that they had stumbled onto a powerful new type of accelerator focusing method. The method was used to build BNL’s next accelerator, the Alternating Gradient Synchrotron (AGS) as well as CERN’s first major accelerator, the Proton Synchrotron (PS). The PS came on line in 1959, and the AGS in 1960.

Scientists at Harvard and MIT then came up with a proposal for the Cambridge Electron Accelerator (CEA), and Livingston became the new laboratory’s director. Livingston performed well during his tenure, and oversaw the rebuilding of the laboratory after an explosion of a hydrogen bubble chamber destroyed much of the laboratory and killed one person. He also supervised the construction of a beam bypass at the CEA, transforming the strong-focusing electron synchrotron into an electron-positron collider.

Livingston had divorced Lois in 1949, and married Margaret (Peggy) Hughes in 1952, but after the latter’s death in 1959, he remarried Lois that same year. In 1967 he became associate director of yet another laboratory, the National Accelerator Laboratory (later renamed Fermi-lab), outside Chicago. He served as chairman of the Federation of American Scientists in 1954 and in 1959. He retired from Fermilab in 1970 and with Lois moved to Santa Fe, New Mexico, where he continued working at Los Alamos. In 1986 he had a prostate cancer operation from which he never fully recovered, and he died on 25 August 1986.

Livingston knew the business of cyclotrons as well as anyone, with the possible exception of Lawrence. He was one of the most important accelerator builders during the age when they were the central tool of nuclear and high-energy physics, a time which may well go down in history as the golden age of U.S. physics.

BIBLIOGRAPHY

Livingston’s papers from 1928 to 1986 can be accessed at the Massachusetts Institute of Technology, Archives and Special Collections. Cambridge, Massachusetts. The records of the Cambridge Electron Accelerator (1952–1974) can be accessed at the Harvard University Archives, Pusey Library, Cambridge Massachusetts, and these contain Livingston’s director’s files, including extensive correspondence and machine design, from 1962 to 1974.

WORKS BY LIVINGSTON

With Ernest O. Lawrence. “The Production of High-Speed Protons without the Use of High Voltages.” Physical Review 40(1932): 19–35.

With Erenst D. Courant and Hartland S. Snyder. “The Strong-Focusing Synchrotron: A New High Energy Accelerator.” Physical Review 88 (1952): 1190–1196.

With John P. Blewett. Particle Accelerators. New York: McGraw-Hill, 1962.

Interview by Charles Weiner and Neil Goldman. 21 August 1967, Harvard University. AIP oral history interview, deposited at the Center for History of Physics of the American Institute of Physics.

Particle Accelerators: A Brief History. Cambridge, MA: Harvard University Press, 1969.

OTHER SOURCES

Courant, Ernest D. “Milton Stanley Livingston 1905–1986.” In Biographical Memoirs 72. Washington, DC: National Academy Press, 1997.

Crease, Robert P. Making Physics: A Biography of Brookhaven National Laboratory, 1946–1972. Chicago: University of Chicago Press, 1999. Especially chapter 7.

Heilbron, John L., and Robert W. Seidel. Lawrence and His Laboratory: A History of the Lawrence Berkeley Laboratory. Berkeley: University of California Press, 1989.

Paris, Elizabeth. “Lords of the Ring: The Fight to Build the First U.S. Electron-Positron Collider.” Historical Studies in the Physical and Biological Sciences 31, no. 2 (2001): 355–380.

Robert P. Crease