Leipunsky, Aleksandr [Лейпунский, Александр; Lejpunskij], b 7 December 1903 in Drahli, Hrodna gubernia (now in Poland), d 14 August 1972 in Moscow. Nuclear physicist; full member of the Academy of Sciences of the Ukrainian SSR from 1934. A graduate of the Leningrad Polytechnical Institute (1926), from 1929 to 1941 he worked at the Ukrainian Physical-Technical Institute in Kharkiv, and from 1933 to 1937 he served as its director. From 1944 to 1952 he worked at the Institute of Physics of the Academy of Sciences of the Ukrainian SSR in Kyiv, and in 1944 served as its director. An ingenious experimentalist, he contributed significantly to the early development of nuclear instrumentation and nuclear-reaction studies in Ukraine. Together with Anton Walter, Kyrylo Synelnykov, and Georgii Latyshev he was the first in the USSR to induce the disintegration of a stable nucleus (lithium) by means of accelerated protons (1932). Leipunsky is internationally known for the first experimental evidence of the existence of the neutrino, obtained in 1934 while he was working as a visiting scientist in Ernest Rutherford’s laboratory in Cambridge, England. The later years of his life were devoted to the development of nuclear-power technology.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 3 (1993).]