Download File
Total Page:16
File Type:pdf, Size:1020Kb
58 An example of the structure of the article 1. In the center of the page: o Initials and surnames of the authors (for example: A.M. Kabyshev, S.P. Krylov) o Full name of the institution the author represents (with indication of the country and city). If the authors are from different institutions, then the correspondence between the author and the institution is established by superscript indices, for example: Title of the article (in bold) A.M. Kabyshev 1 , B.K. Sadykov 2 1 L.N. Gumilyov Eurasian National University, Astana, Kazakhstan 2 Institute of Nuclear Physics, Almaty, Kazakhstan * E-mail of one of the authors. 2. Abstract (no more than 250 words). 3. Keywords (no more than 10 words). 4. Text of the article. 5. References. 6. Acknowledgments. 7. Illustrations (figures, diagrams, tables, etc.) with captions submitted on separate pages. 8. Information about the authors. Note. Articles without abstracts, exact coordinates of authors (e-mail of one of the authors), electronic version and short title of the article will not be accepted. 59 60 International Symposiums Exotic nuclei - EXON Dear readers, From 5 to 10 September 2016 Kazan (Russian Federation) hosted the Interna- tional Symposium on one of the most important and the most rapidly developing areas of nuclear physics - the physics of exotic states of nuclei-"EXON 2016". The organizers of the Symposium were the five largest scientific centers, where this area is being successfully developed, -the Joint Institute for Nuclear Research in Dubna, the GANIL National Center (France), the RIKEN Research Center (Japan), the GSI Helmholtz Centre for Heavy Ion Research (Germany), the National Su- perconducting Cyclotron Laboratory (Michigan, USA). The Symposium was held with the active participation of Kazan Federal University (KFU). Kazan Univer- sity was founded in 1804 by the renowned mathematician Lobachevsky, and has its own traditions. V.I. Ulyanov (Lenin), the writer L.N. Tolstoy, and other famous peoplestudied there. Currently, the most complex physical experiments conducted with the use of the large accelerators facilities and requiring huge financial investments cannot be performedbya single, even highly developed, country. An example of this might be the construction of the Large Hadron Collider at the European Orga- nization for Nuclear Research (CERN), the NICA collider and heavy-ion accel- erators at the Joint Institute for Nuclear Research in Dubna, which includes 20 member countries. Therefore, these studies are carried out in close cooperation of research centers of several countries, each of which makes its financial and in- tellectual contribution to the construction of the largest facilities. Allowing one to penetrate into the secrets of matter more and more deeply and obtain new infor- mation not only for physics but also for other fields of science such as astronomy, physics of condensed matter, modern technologies. These fundamental studies and methods used in them are also of great importance forthe related areas of science and technology, such as nanotechnology, medicine, microelectronics. This is the eighth Symposium on exotic nuclei held in Russia. The first sym- posium took place 25 years ago in 1991 in Foros (Crimea), later symposiums were held on Baikal Lake, in Peterhof, Khanty-Mansiysk, Sochi, Vladivostok, and Kaliningrad (see themap). The first symposium (EXON1991) was dedicated to the results of coopera- tion of JINR (Dubna) and GANIL (Caen, France). After a while due to the great interest in this research and new experimental possibilities that emerged with the launch radioactive ion beam facilities the collaboration extended to five research centers, which were the co-founders of the subsequent EXON work- shops.Already in 2004, the co-founders of the symposium, held in Peterhof (near St. Petersburg) were GSI, GANIL, RIKEN, JINR, and later MSU (Michigan, USA). The Symposium "EXON 2016" was attended by about 160 scientists from 20 countries, most of whom are leading experts in the field of nuclear physics. The most representative delegations were from Germany, France, Japan, and USA. Research centers of these countries are interested in developing cooperation with JINR and scientific centers of Russia. The scientific program included invited talks on important areas of the 61 physics of exotic nuclei and new projects of the largest accelerator complexes and experimental facilities. In addition, discussions with the participation of leading scientists from various research centers in the world were organized. They dis- cussed issues of cooperation in the field of fundamental physics of heavy ions and applied research. At the opening of the Symposium, which was held in the old assembly hall, thespeech was made by the representatives of the Kazan (Volga region) Federal University and the Joint Institute for Nuclear Research, which celebrates the 60th anniversary of its foundationthis year. Exoticism in Nuclear Physics It has been 25 years since the first International symposium on exotic nuclei (EXON) was held. One of the main trends in modern nuclear physics is to ob- tain and study the properties of nuclear matter (or nuclei) in extreme state. The appearance of powerful accelerators of heavy ions allows the synthesis of such nuclei. Exotic nuclei are basically a nuclear matter in a very unusual state. There are several unusual states that define nuclei as exotic: nuclei of large angular momentum ("rabidly" rotating nuclei), nuclei of high excitation energy ("hot" nu- clei), strongly deformed nuclei (super and hyper-deformation, nuclei in unusual configuration form), nuclei with abnormally high number of neutrons or pro- tons (neutron- rich and proton-rich nuclei), and super-heavy nuclei up to atomic number of protons Z>110. The study of the properties of nuclear matter in its unusual state provides the important information about the properties of the mi- crocosm and thus allows us to simulate various processes that take place in the Universe.Since 1991, we have been holding Internationalsymposiums on exotic nuclei, which discuss the latest results on the properties ofexotic nuclei obtained by collaborations of various research centres. The crucialpoint of the symposium of 1991 was the joint results obtained in Dubna and inGANIL; that is why com- ing up with an idea to hold the first symposium EXON, we set ourselves several tasks: 1. The symposium should summarize the latest results obtained on the actual subject in collaboration with other research centres. 2. The symposium should take place only in exotic locations of Russia 3. The symposium results should promote decisions on future programme of the joint experiments. 62 4. All the symposiums should be based on local universities under active support and immediate participation of the students and teachers of these uni- versities. We seem to have managed to cope with all the set tasks according to the evidence of geography of the symposium venues. The entire topic of the symposium can be divided into the following parts: synthesis and properties of neutron-rich nuclei of light and the lightest elements, synthesis and properties of superheavy elements, rare processes and decays. The information about resonant states in 4H and5H system has been obtaine- dat LNR accelerators. The joint FLNR - GANIL - RIKEN experiment investigat- edthe super heavy isotopes of hydrogen and helium. Striking information was re- ceivedthrough the experiments on search of tetra neutron in GANIL and RIKEN. The study ofsuch systems is of great importance for understanding the increas- ing nuclear stabilitywith the increase of the number of neutrons (the existence of neutron systems of 20 and 40 neutrons had been long since predicted), which, in its turn, isof great interest to astrophysics (neutron star). A fundamentally new and somewhat unexpected information has been re- ceived for neutron-rich nuclei located near the magic neutron numbers N = 20 and N = 28. The number of neutrons near these magic numbers turned out to no longer play a stabilizing role. In this respect new magic numbers 6, 16 and 32 were found; at that, deformation is of great significance in stability of these nu- clei. A great number of theoretical and experimental works were devoted to re- search of such nuclei states. Here, for the first time therehad been used a method based on nuclear magnetic resonance, as well as methodsof sensitive gamma spectroscopy by using such detectors as EXOGAM, AGATAand EUROGAM. Di- rect measurements of nuclear masses where N = 20-28 werealso made. Exotic nuclei show unusual properties in reactions with other nucleias well. There have recently been received a number of interesting results in the study of excitation functions of full cross sections of reactions, fusion-fission reactions and particle evaporation from the excited compound nucleus. These reactions were studied in the beams of radioactive nuclei 6He,8 He,11 Li, and others. An essential increase in fusion cross-section at the energies close to the barrier was captured. A suffi- cient decrease of full cross-sections of reactions due to collapse of the interacting nuclei was noticed in case with weakly bound nuclei at high energies. This un- usual result confirms the existence of a "coat" made of two interacting neutrons in 6He nucleus. This trend of research of reaction with exotic nuclei is one of the major ones in the programme of radioactive beam-factories. and super heavy During the Symposium, the results of recent experiments on the synthesis and study of properties of nuclei of new superheavy elementswere discussed: the discovery of new superheavy elements shows high efficiency of international cooperation. Interesting results were obtained in joint experiments on chemical identification of elements 112 and 114, performed at the Laboratory of Nuclear Reactions (FLNR) JINR (Russia), the GSI (Germany), and the Paul Scherrer In- stitute (Switzerland). A striking example of cooperation with US scientists is an experiment on the synthesis of element 117, held at the cyclotron of FLNR JINR under the leadership of Yu.Ts.Oganessian.