2. The early Soviet nuclear program

Such complacency was sharply at odds with reality, and especially ignorant of the progress made by Soviet nuclear scientists. It will be recalled that the Soviets had had a sophisticated group of physicists and a reasonably progressive (though generally imitative) nuclear program before the German invasion of June 1941. Josef Stalin’s regime during the 1930s limited the movements of physicists and other scientists, frequently preventing them from traveling abroad and making it difficult for their foreign colleagues to visit them. Peter Kapitsa was kept from returning to his work in Cambridge in 1934. Some were tossed into prison or executed. Despite the odds, physics research went forward. In Britain, H. G. Wells had inspired and frightened Leo Szilard by imagining an atomic bomb. In 1908 Alexander Bogdanov published the novel Red Star, in which Marxist utopian Martians use atomic power to help achieve the good society. Research on the nucleus began in earnest in the Soviet Union following the annus mirabilis, 1932, in which James Chadwick at the Cavendish Laboratory discovered the neutron, Cal Tech’s Carl Anderson found the positively charged electron (positron), and Ernest Lawrence used his newly built cyclotron to accelerate protons around a magnetic track. Thereafter Abram Ioffe, head of the Physicotechnical Institute in Leningrad, organized an international physics conference, to which many luminaries and top young Russian physicists came. Within a year, there were four nuclear physics labs in operation at Ioffe’s institute, headed by Igor Kurchatov. A cyclotron was built at the Leningrad Radium Institute, in the charge of V I. Vernadskii and to some extent in competition with Ioffe’s establishment, but by the late 1930s Kurchatov had effectively commandeered the machine for his own experiments. In other nuclear labs, in the Ukraine and in Moscow, work proceeded fitfully during the mid-i930s, constrained not by a lack of scientific sophistication but by political rivalries, limited funding, and harassment and worse from the regime.14

The discovery of fission in late 1938 and its publicity early in 1939 energized the Soviet physics community. Experimentation sped up in all the labs and produced exciting results, concerning the number of neutrons released during fission and circumstances under which a chain reaction might occur, and including the type of moderating agent that would most effectively allow neutrons to strike nuclei and set the chain in motion. Like their counterparts in Europe and the United States, few Soviet physicists thought in 1939 that practical applications of nuclear energy would soon be realized. David Holloway notes that in early 1941 the physicists Yuli Khariton and Yakov Zeldovich wrote a paper suggesting that 10 kilograms of uranium 235 could yield ‘a chain reaction... with the liberation of tremendous quantities of energy’—an overestimate, but much closer to the correct answer than most previous overestimates—and pointed out that compressing the uranium with an explosive would induce the reaction to take place. Holloway rightly compares this paper (which was neither published nor attended by the authorities) to the Frisch-Peierls memorandum of the same period, though he also notes that the Russians failed to suggest how a quantity of the 235 isotope might be produced, in this way unlike Frisch and Peierls. Soviet physics ran on tracks parallel to those laid out in the West, or perhaps just behind on the same tracks. Niels Bohr, virtually alone, noticed and admired Soviet progress, and understood that it would not be undone or reversed. But when Germany attacked the Soviet Union on 22 June 1941, work on fission was for the time being shelved in favor of defense research more likely to be productive in the short run. Kurchatov abandoned his fission experiments; Ioffe’s institute was moved east and left unsettled.15

Like the British and the Americans, before 1941 Soviet scientists gave little thought to the possibility of atomic weapons, believing them impractical. Peter Kapitsa went to work on, among other things, the production of liquid oxygen (for which Russian industry, he wrote Stalin in disgust, was altogether unprepared), and monitored Western physics and physicists as best he could. Good intelligence on the infant state of the German nuclear program gave further disincentive to push forward into the expensive unknown. But in the fall of 1941 the Soviets learned of the recently written MAUD Report, in which British scientists concluded that the production of atomic bombs might be feasible. Slowly the state reacted. In early 1943, Stalin authorized a limited program to build a nuclear weapon. The decision coincided with the initiation of a Soviet counteroffensive out of Stalingrad, codenamed Operation Uran—‘Uranus’, or more likely ‘uranium’. Stalin did not, in Holloway’s view, believe a Soviet atomic bomb would ever prove decisive against the Germans. Instead, ‘the project he started is best understood as a rather small hedge against future uncertainties’. Igor Kurchatov, who had vowed not to shave his robust beard until ‘Fritz’ was beaten, was put in charge of the project, and in early March Foreign Minister Molotov sat him down with a stack of papers smuggled out of Britain by Soviet agents. These materials, concerning especially isotope separation techniques and the morphology of a chain reaction, were, according to Kurchatov, of ‘huge, inestimable significance for our state and science’.16

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