Lev Vladimirovich Mysovsky (18.02.1888-29.08.1939) was a Soviet physicist and a Doctor of Physical and Mathematical Sciences. He was born in Saratov. He graduated from St Petersburg University (1914) and was retained at the department. From 1918 he worked at the State X-ray Institute, and from 1922 he was head of the physics department of the Radium Institute (Leningrad).
His research concerned cosmic-ray physics, nuclear physics and accelerator technology. In 1925 he measured the absorption of cosmic rays at a depth of 10 m in a lake, which was one of the conclusive proofs of their existence. He detected the change in the intensity of cosmic radiation with atmospheric pressure, the barometric effect (1926), and proved that cosmic radiation differs in its properties from the radiation of radioactive substances. In 1925 he proposed a method of recording charged particles by means of thick-layer photographic emulsions. In 1934 he proved the presence of neutrons among the components of cosmic rays.
He initiated gamma-ray flaw detection (1926). Together with I. V. Kurchatov, B. I. Kurchatov and L. I. Rusinov he discovered (1935) nuclear isomerism in artificially radioactive bromine, and with I. V. Kurchatov he concluded that the probability of capture of fast neutrons is very small. He was one of the first to put forward (1922) the idea of an accelerator of charged particles. In 1932, on Mysovsky's initiative, construction began at the Radium Institute of the first large Soviet cyclotron, which was started up in 1937.