Although quite a bit has been written about Igor Kurchatov, of particular interest to us is what his colleagues and fellow workers have got to say about hi m- all those who worked shoulder to shoulder with him on the Soviet nuclear project. One such publication is just off the press in its second edition, and this is the book Man of the Century: Yuli Borisovich Khariton (M., 2002)-a sampling of reminiscences of Kurchatov's coworkers, pupils, friends, his near and dear ones. Together with Igor Kurchatov, Yuli Khariton forged our country's nuclear shield. He has contributed a few articles where he recalls at great length about Igor Kurchatov. We have selected what seem to us to be the most illuminating passages from this book of reminiscences. Concerning Some Myths and Legends About the Soviet Nuclear Project (coauthored with Yuri Smimov)
... Two all-important documents have been declassified for the public. These are the hand-written letters of Igor Kurchatov to Mikhail Pervukhin, Soviet deputy premier (both are available in the original only, no copies). The first letter, dated March 7, 1943, contains 14 pages, and the other, of March 22, 1943, has eight.
Kurchatov collates the results of Soviet physicists with intelligence data and, what is most important, prioritizes areas of work on the nuclear problem, the way he sees it.
I. Kurchatov says this in part: "It was very important for us to learn that Frisch has confirmed the phenomenon of spontaneous fission of uranium discovered by the Soviet physicists Georgi Rerov and Konstantin Petrzhak, a phenomenon that can create in the uranium mass initial neutrons touching off an avalanche-type process. Because of this phenomenon it is impossible, up to the very moment of explosion, to keep
all of the uranium bombing charge in one place. The uranium should be separated into two parts which, at the moment of detonation, should be brought closer to each other at a rather high relative velocity. This mode of uranium bomb activation... is not at all new to Soviet physicists... An analogous technique was suggested by the Soviet physicist G.N. Rerov; he calculated the velocity for bringing together both halves of the bomb... The works published in 1939 and 1940 by Joliot, Hallbahn and Kowarski in France, and those of Andersen Fermi, Cinna and Szilard in America as well as research works carried out in my laboratory give the same value for the number of secondary neutrons per fission act and about the same general picture of their distribution per energies..."
It is revealing that from the very start Igor Kurchatov was taking a sober and quite critical view of intelligence reports. He said it bluntly, "Certain conclusions, even on rather important parts of the work, appear dubious to me, and some of them-poorly substantiated." And he did not conceal his surprise that, for instance, Western physicists preferred the diffusive method to the method of centrifugal separation of isotopes.
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For all his caution about intelligence reports, Igor Kurchatov was quick to notice, as he put it, "fragmentary remarks concerning the use in the 'uranium pile' not only of uranium-235 but also of uranium-238" and that "maybe the burnup products of nuclear fuel in the 'uranium pile' could be used instead of uranium-235 as stock material for the bomb". And Kurchatov has this to say in his letter to Mikhail Pervukhin of March 22, 1943: "With an eye to these remarks, I have closely considered the latest works published by the Americans in Physical Review on transuranium elements (ekarenium-239 and ekaosmium-239)* and could
* No doubt, this is in reference to the articles by E. McMillan, F. Abelson and L. Turner published by the journal Physical Review in the summer of 1940. In present terminology ekarenium stands for neptunium, and ekaosmium - for plutonium.-Yu. Khariton.
see a new trend in the solution of the entire uranium problem... The prospects of this trend are captivating indeed."
... Showing a physicist's irreproachable intuition, Igor Kurchatov in fact anticipated the prospects as he concluded: "In keeping with all present theoretical ideas the hitting of a neutron onto the nucleus of ekaosmium should be accompanied by a vigorous release of energy and emission of secondary neutrons... It could be isolated from the 'uranium pile' and used as material for an ekaosmium bomb. Consequently, the bomb will be made from 'nonterrestrial' material that has disappeared on our planet. Obviously, by thus addressing the problem, there would be no need for separating isotopes of uranium used both as a fuel and as an explosive."
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It is quite clear now that from its very first days and first steps the Soviet atomic project, relying on the solid foundation laid by truly remarkable works of Soviet physicists, got an absolutely correct start-out program thanks to Igor Kurchatov.
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That was captivating and extremely intensive work done with much abandon and enthusiasm. This patriotic effort in the novel and responsible job was personified by Igor Kurchatov himself.
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...At first we were catching up with our American colleagues who created an A-bomb by mid-1945. But in August 1949 this perilous monopoly of the United States on nuclear arms was done away with. Afterwards Soviet physicists made a break forward and, on August, 12, 1953, were the first in the world to test a real hydrogen charge ready for use in the form of a bomb. The idea of this charge was suggested by Andrei Sakharov.
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My Teachers and Friends
(From Yuli Khariton's Speech in the House of Scientists at Sarov)
In 1955 Igor Kurchatov supervised tests for the last time. After a series of small- charge blasts a hydrogen bomb with a TNT equivalent of 1 million 600 thousand tons (1.6 megatons) was dropped from an aircraft and detonated. I can well cite this figure calmly, for it was reported by the main US speaker at an international conference in 1987. And he got it from the declassified archives of US intelligence.
As Igor Kurchatov reported to the government commission on the results of the tests, he said, "The land was mutilated all over." That's true: for many kilometers away from the blast center the shock wave knocked out clods the size of a Zhiguli car.
Abram Joffe and Igor Kurchatov
(From Yuli Khariton's Speech in the House of Scientists at Sarov in 1980)
... As what was most essential for this country's development and defenses had been reached, Igor Kurchatov gave himself whole-heartedly to the job of realizing the ideas of controlled thermonuclear fusion advanced by a group of Soviet Scientists. These ideas received great impetus soon. Kurchatov maintained that they should be implemented at a very fast pace. He had great belief the time was not far off for thermonuclear fusion to become a potent and well-nigh inexhaustible source of power for humanity. He bent all his energies toward proper organization of this work for which large and costly setups were needed, and which needed fresh blood. Industry had to be involved in the effort of building such setups. Kurchatov had a remarkable ability to win people's minds and hearts, he succeeded here, too, in building up new teams that joined in the effort.
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In his last years Igor Kurchatov devoted ever more time and energy to thermonuclear fusion. Just a few days before his sudden death he went to the Ukrainian Physicotechnical Institute. He managed to secure support from the Central Committee of the Communist Party of the Ukraine for building new premises and setups in Kharkov. He came back elated-yet another major center was to be created, and victory was in sight over one of the most forbidding jobs that physicists were confronting.
Kurchatov virtually consumed himself in his selfless endeavor. Death overtook him during a scientific discussion.
Prepared by Olga BAZANOVA.
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