Il'ja M. Frank was a preeminent Soviet physicist whose pioneering work fundamentally advanced the understanding of electromagnetic phenomena in nuclear physics. Born in Leningrad on October 23, 1908, he graduated from Moscow State University in 1930 and began his scientific career at the State Optical Institute as a senior scientific officer under Professor A.N. Terenin. In 1934, he joined the P.N. Lebedev Institute of Physics of the USSR Academy of Sciences, marking the beginning of his transition from optical physics to nuclear physics. Frank was appointed Professor at Moscow State University in 1944 and simultaneously led the Atomic Nucleus Laboratory at the Lebedev Institute, establishing himself as a leading figure in Soviet physics during a critical period of scientific development.
Frank's most significant contribution was his theoretical explanation of the Cherenkov effect, which he developed with Igor Tamm in 1937, providing the crucial framework for understanding how charged particles emit light when traveling through transparent media at speeds exceeding the speed of light in that medium. Their groundbreaking work elucidated the phenomenon discovered by Pavel Cherenkov in 1934, demonstrating that the effect occurs due to electromagnetic shock waves created by superluminal particles, a discovery that fundamentally transformed particle detection methodologies. The mathematical formulation of this process, now known as the Frank-Tamm formula, became an essential tool for quantifying energy radiation in particle physics and enabled the development of Cherenkov counters that revolutionized high-energy physics research. This seminal work directly contributed to major advances in nuclear physics by providing researchers with precise methods for detecting and measuring the velocity of high-speed particles, facilitating numerous discoveries of elementary particles including the antiproton.
Beyond his Nobel Prize-winning achievement, Frank made substantial contributions to neutron physics and reactor design, playing a pivotal role in the development of the USSR's first uranium-graphite reactor F-1 in 1946 through his leadership at the Radiation Monitoring Laboratory of the Skobeltsyn Institute. From 1957 until the end of his career, he directed the Laboratory of Neutron Physics at the Joint Institute for Nuclear Research in Dubna, where he oversaw the construction and application of the neutron fast-pulse reactor for advanced spectroscopy techniques. Frank was elected a Corresponding Member of the USSR Academy of Sciences in 1946, became a full Academician in 1968, and received the Stalin Prize in 1946 and 1953 along with the USSR State Prize in 1971 for his extensive scientific contributions. His enduring legacy continues to influence particle physics through the ubiquitous application of Cherenkov radiation detection in modern experiments worldwide and his foundational role in establishing Soviet nuclear physics as a major scientific discipline.
