Milton Stanley Livingston (May 25, 1905 – August 25, 1986) was an American accelerator physicist, co-inventor of the cyclotron with Ernest Lawrence, and co-discoverer with Ernest Courant and Hartland Snyder of the strong focusing principle, which allowed development of modern large-scale particle accelerators.

Livingston was the chairman of the Accelerator Project at Brookhaven National Laboratory, director of the Cambridge Electron Accelerator, a member of the National Academy of Sciences, a professor of physics at MIT, and a recipient of the Enrico Fermi Award from the United States Department of Energy.

The family moved to California when Livingston was five years old, and he grew up in Burbank, Pomona and San Dimas.

At Lawrence's prompting, Stanley quickly wrote up his thesis and submitted it in April 1931 so that he would be eligible for an instructorship the following year.

Raymond Birge started asking questions about nuclear physics, and Livingston had to admit that he knew nothing about the work of Ernest Rutherford, James Chadwick, and Charles Drummond Ellis, and had not read their 1930 monograph Radiations from Radioactive Substances.

[2] In what would become a recurring pattern, as soon as there was the first sign of success, Lawrence started planning a new, bigger machine, which became known as a cyclotron.

Lawrence and Livingston drew up a design for an $800 27-inch (69 cm) cyclotron in early 1932, with a magnet that weighed 2 tons.

Lawrence then found a massive 80-ton magnet that had originally been built to power a transatlantic radio link during World War I, but was now rusting in a junkyard in Palo Alto.

In April 1932, John Cockcroft and Ernest Walton at the Cavendish laboratory in England announced that they had bombarded lithium with protons and succeeded in transmuting it into helium.

[4] Livingston returned to MIT soon after the end of the war, but in 1946 a consortium of universities including MIT banded together to create the Brookhaven National Laboratory in Long Island, New York, as a facility for carrying out Big Science research activities that were beyond the resources of a single academic institution.

Morse was appointed as Brookhaven's first director, and he asked Livingston to take charge of building an accelerator for the new national laboratory.

[13] Livingston was unable to stay at Brookhaven to see the Cosmotron project completed because he faced losing his tenure at MIT, and elected to return there in 1948.

[2] At MIT he taught classes, and participated in a 1950 experiment by the Los Alamos National Laboratory to investigate the lifetimes of short-lived fission products.

[1] He still thought about accelerators, though, and in 1952, along with Ernest Courant, Hartland Snyder and J. Blewett at Brookhaven, developed strong focusing, the principle that the net effect on a particle beam of charged particles passing through alternating field gradients is to make the beam converge.

[4][14] The advantages of strong focusing were then quickly realised, and deployed on the Alternating Gradient Synchrotron, which achieved 33 GeV in 1960.

[13] A plan to build a synchrotron at MIT and Harvard also came to fruition under Livingston's leadership, resulting in the Cambridge Electron Accelerator (CEA), which became operational in 1962.

He continued to occasionally work as a consultant at the nearby Los Alamos National Laboratory, and sometimes acted as an administrative judge for the Nuclear Regulatory Commission.