Leo Szilard (11.02.1898-30.05.1964) was a physicist. He was born in Budapest. He graduated from the University of Berlin (1922) and worked there in 1925-32. In 1935-38 he was in laboratories in London and Oxford, in 1939 —42 at Columbia University, in 1942 — 46 at the Metallurgical Laboratory of the University of Chicago, and from 1946 professor at that university.
His research was in the fields of nuclear physics, nuclear engineering, thermodynamics, X-ray crystallography, the theory of accelerators, molecular biology, genetics and immunology. He was one of the first to prove that secondary neutrons are emitted in the process of fission of uranium nuclei, and he substantiated the possibility of a self-sustaining nuclear fission reaction developing in uranium (1939). Together with W. Zinn he obtained the value of the mean number of secondary neutrons per fission event (1939). He put forward the idea of using graphite as a neutron moderator (1939). His research also concerned calculations of the critical mass of uranium and the control of the nuclear chain process. He proposed the use of heterogeneous systems and pointed out the possibility of fission by fast neutrons.
His research also concerned the physics of accelerators. He put forward the idea of the linear resonance accelerator (1928), the cyclotron (1929), the principle of autophasing (1934) and others. However, this work remained unknown for a long time and had no influence at all on the development of accelerators and of accelerator technology.
In 1934, together with T. Chalmers, he discovered the destruction of a chemical bond under the action of neutrons (the Szilard–Chalmers effect). His biological work concerned the study of the regulation of cellular metabolism, the formation of antibodies, the processes of ageing and the functioning of the central nervous system, and the molecular basis of human memory.
He was widely active in public life. He was one of the initiators of the Pugwash movement. He was the author of a number of memoranda on questions connected with new discoveries in physics, with the problems of the peaceful use of atomic energy, and with the control of the production of nuclear bombs. Member of the National Academy of Sciences of the USA (1961). The A. Einstein Award and the Atoms for Peace Award (1959).