Conferences

Half a century since the discovery of cold nuclear fusion
has been celebrated in Yerevan

On 20 - 24 November, Yerevan hosted the International Conference "50 years of cold fusion," organized by the National Academy of Sciences of the Republic of Armenia and the Joint Institute for Nuclear Research. Scientists from different parts of the world, including Europe, Asia and America, gathered to participate in the Conference.

September 2024 marked 50 years since the discovery of cold fusion reactions. In 1974, a new class of reactions was discovered in Dubna under the supervision of Yuri Oganessian - cold fusion reactions of massive nuclei. For half a century, these reactions have been used in world practice for the synthesis and investigation of the properties of transactinide elements. This technique allowed leading laboratories of JINR, Germany and Japan to synthesize elements with atomic numbers from 107 to 113 for the first time.

The opening ceremony of the Conference was attended by JINR Director Academician of the Russian Academy of Sciences Grigory Trubnikov, President of the National Academy of Sciences of the Republic of Armenia Ashot Saghyan and Academician-Secretary of the Department of Natural Sciences of the National Academy of Sciences of the Republic of Armenia Ruben Harutyunyan.

Grigory Trubnikov emphasized in his opening remarks that the year of the 50th anniversary of the first experiments on cold fusion of atomic nuclei is symbolic not only for JINR, but also for all world laboratories that study nuclear reactions and the tradition of holding regular conferences to discuss the results of research on the synthesis and properties of superheavy elements should be preserved. "Many elements have been synthesized in collaboration between Dubna, Germany, the United States and other countries and the very names of some of these elements: hassium, darmstadtium, nihonium symbolize international cooperation. We currently carry out joint experiments with our European and now Chinese colleagues," JINR Director highlighted.

President of the National Academy of Sciences of the Republic of Armenia Ashot Saghyan spoke about the activities and structure of the NAS RA in his speech. "Our Academy implements the most important research of global significance in the field of astrophysics, information technologies, applied mathematics and mechanics, physics, chemistry, biology, Armenology and a number of other scientific fields," he highlighted. Ashot Saghyan emphasized that today, the Academy hosts many world-famous scientists from different countries, who he values cooperation very highly with. "This Symposium dedicated to the 50th anniversary of the discovery of cold fusion reactions is a good opportunity not only to remember the past, but also to consider the entire problem of the synthesis of superheavy elements from a modern viewpoint and capabilities," President of the NAS RA said.

Commenting on the event, the Scientific Leader of the Laboratory of Nuclear Reactions Academician of the Russian Academy of Sciences Yuri Oganessian stated that the significance of any discovery becomes obvious only at a historical distance. "The discovery of cold fusion has already been replaced by others; elements heavier than those obtained by cold fusion have been discovered. At first, scientists in Dubna worked with this technique, later, many laboratories around the world joined in and very effectively. There was a great deal of interest in this topic, yet new opportunities and new ideas also appeared. In this sense, cold fusion is only part of the path in the history of the synthesis of artificial elements, when a man began to do what nature does, but in a different way, based on all the knowledge available at the moment," Yuri Oganessian explained. The techniques replace each other: first, a group of American scientists supervised by Glenn Seaborg developed a technique of bombarding actinide targets with neutrons, protons, deuterons and helium nuclei, afterwards, a technique of bombardment with heavy ions was developed that started in Dubna. "Later, cold fusion was discovered that showed that in this large transformation, in which many particles participate, there are certain configurations that physicists call magical and that start to play a role due to the fact that the interaction of these particles is greater than average. Today, we have already moved from cold fusion to reactions with ⁴⁸Ca that gave us the opportunity to obtain all the elements that cold fusion does not "reach": from 114 to 118," Academician Oganessian said. He added that implementation of experiments on obtaining elements 119 and 120 will be a continuation of experiments on obtaining the above-mentioned elements.

The Conference included sections dedicated to cold nuclear fusion of superheavy elements (SHE), nuclear reactions with heavy ions, as well as physical and chemical properties of SHE. The discussion focused on the mechanisms of fusion reactions, the current state of facilities on the synthesis and investigation of SHE in leading global centres and also prospects for the development of experimental and theoretical research.

Reports of many world-known scientists in the field of synthesis and description of properties of chemical elements were presented at the Conference. Among the speakers were researchers from Bulgaria, Great Britain, Germany, Israel, China, Poland, Russia, Romania, France, Switzerland, Sweden and Japan.

At the beginning of the Conference, Yuri Oganessian presented a report on the cold fusion of massive nuclei. Peter Moller (Lund University, Sweden) spoke about the chronology of significant theoretical developments that resulted in the current understanding of the stability of heavy elements. Christoph Dullmann (Germany) reported on the use of the cold fusion technique in the investigations of the Helmholtz Centre for Heavy Ion Research. Zhang Feng-Shou (Beijing Normal University, China) delivered a report on various ways of synthesizing superheavy elements.

Based on the information from the JINR Press Office