Donald William Kerst (born 1.02.1911) is an American physicist and a member of the National Academy of Sciences (1951). He was born in Galena. He graduated from the University of Wisconsin (1934). In 1938 — 43 he worked at the University of Illinois, in 1943—45 at the Los Alamos laboratory and in 1957—62 at the J. Hopkins laboratory of the General Dynamics Corporation. In 1962—80 he was professor at the University of Wisconsin.
His research was in the field of nuclear physics, accelerator technology, plasma physics and thermonuclear research, and radiography. In 1940 he invented the betatron. He was the first to consider (1955) the possibility of using magnetic fields with spatial variation in cyclic accelerators, fields whose strength varies periodically both in azimuth and in radius. In 1956 he put forward the idea of colliding beams for accelerating particles.