Their names - in the history of the Institute

First person story

In memory of N.K.Skobelev, published in No.11, 2012

On 1 March, 2012, a seminar from the series "History of discoveries - from the first person" was held at the JINR Museum of History of Science and Technology. This project was opened five years ago aimed at piecing the history of Dubna discoveries told by their authors. This time, the author of the discovery "Delayed fission of atomic nuclei" N.K.Skobelev spoke in the first person.

The history of radioactivity traditionally leads from Becquerel but almost 40 years before him, the inventor Abel Nieps had observed the blackening of photographic paper when in contact with uranium salts. Nieps reported his observation to the Academy of Sciences but the Academy did not find an explanation for this phenomenon and later completely forgot about it. With Fermi, the story was different. Fermi could have discovered nuclear fission back in 1934, four years before Gunn and Strassmann and they were already ready for it; then the whole history of the atomic bomb and the whole history of Europe could have turned out completely differently and the first atomic bombs would have flown to completely different cities.

What is the difference between a regular lecture on discoveries and a story by the authors of these discoveries? At some point, lecturers put aside what can be read in textbooks and begin to talk about their experiences in person. For Skobelev, the history of nuclear physics became part of his biography at the end of 1957, during his diploma practice at the Kurchatov Institute. And none other than Georgy Flerov communed him. The topic of the thesis was the measurement of the half-life of spontaneous fission of americium-241; before that, it was measured by Segre but the result seemed doubtful to Flerov and the young man had to double-check the classics of nuclear physics that he did not begin without some fears.

This is the first plot in the scientific biography of N.K.Skobelev. And afterwards, events moved to Dubna, where the construction of the latest heavy ion accelerator was completed. It was 1960 and then 1961. It was nearing 7 November, the staff of the Laboratory of Nuclear Reactions, mobilized for the synthesis of the element 102 was preparing for a decisive assault. A representative of the State Committee for Atomic Energy was sitting at the remote control, ready to report upstairs about success. But I didn't have to report. What was mistaken for 102 turned out to be a signal of another, already open element. And after that, the paths to the unknown diverged.

Nikolay Skobelev in the experimental hall

Group Leader S.M.Polikanov with two employees carried out further investigation of the "mysterious stranger" at the Kurchatov Institute and Flerov, after the first disappointment had passed, assembled a new team, this time headed by V.A.Druin that continued the assault of 102 and 104 - the assault that went into a three-year siege. Who was right? Flerov believed that his beloved student Serezha Polikanov was afraid of difficulties. And Polikanov saw in the "mysterious stranger" a subject worthy of independent scientific research. It was soon found that this stranger is a well-known americium with an unusual half-life that by accident coincided with what theorists had predicted for 102. Thus, the first spontaneously fissionable isomer was discovered.

N.K.Skobelev became one of the co-authors of the first publication on "anomalous americium" that was later referred to as "Polikanov and others" but his own discovery was to come. Georgy Nikolaevich that had belatedly evaluated the "stranger", gave the order to look for spontaneously dividing isomers with a long half-life. And what happened again is that can be attributed to the cross-cutting plots of the history of science. They were looking for the element 102 - they stumbled upon a spontaneously fissionable isomer. They searched for a spontaneously fissionable isomer - they discovered another previously unknown type of radioactivity: delayed nuclear fission.

After a "brief moment of celebration", daily work began again. Afterwards - almost a detective story with a magazine publication. A few years later, it was the turn to "butt heads" with the committee on inventions and discoveries. There was no direct evidence that fission was indeed preceded by K capture and it inhibited the registration of the discovery but the belief in K capture was and persisted until it passed into confidence after the X-ray K-line of the daughter element had been isolated in the West, repeating the experiment of the Dubna group.

But let's come back "to the present day" - in the early 1970s. Against the background of episodes from the history of science, in which Shakespearean passions boil, delayed fission looks like a pastoral picture but this is a good story with a strong beginning and a happy ending: in 1975, the Committee on Inventions and Discoveries registered the discovery of delayed nuclear fission, it was listed in the State Register of Discoveries of the USSR. Is it worth clarifying that Flerov co-authored the discovery? Worth it! Because sometimes he himself crossed out his last name, while saying that good gratitude is better than bad co-authorship. True, if we are talking about publication. But not only. So, he refused to become a co-author of the discovery of the element 102.

Vladislav Kuznetsov and Georgy Flerov

Another co-author was the chief engineer of the Laboratory V.I.Kuznetsov.

Nikolay Konstantinovich showed a diploma of discovery, "Each author receives a diploma in which his surname comes first."

"Kolya, you deserved a cup of tea," V.A.Shchegolev summed up his story, to the applause of the participants, nudging the speaker a modest treat.

Alexander RASTORGUEV