Prof. Alexei Alekseevich Ogloblin has passed away

Yesterday (23 February 2021), just two months short of his 90th birthday, our dear friend and colleague, Alexei Alekseevich Ogloblin, has passed away. He was an outstanding physicist, promoter of science, and a talented teacher; Doctor of Physical and Mathematical Sciences, and Professor at the Kurchatov Institute, where he has worked since 1954. He was the Head of the Department of Nuclear Physics and Beam Technologies of the Kurchatov Nuclear Physics Complex (KNPK). He excelled in the field of nuclear physics, nuclear reactions, and applications of nuclear physics. His most prominent achievements include:

  • Development of a method for measuring the radii of nuclei in short-lived excited states and the first observation of such states with anomalously large sizes.
  • Synthesis and study of nuclei beyond the neutron stability (6 out of 12 known cases).
  • Detection of states of unusual structure in exotic nuclei.
  • First observation of deep-bound hole states of nuclei.
  • The first study of reactions with lithium ions, detection of the mechanism of transfer of nucleon clusters, observation of highly excited alpha-cluster states.
  • Study of the nuclear rainbow, the interaction of nuclei at small distances, the equation of state of cold nuclear matter, and the mass of neutron stars.
  • The first independent confirmation of the phenomenon of cluster radioactivity, observation of new cases of cluster decay and their research.
  • Diagnostics of wear of synthetic machine parts using radioactive beams.
  • The first Russian production of 201Tl and 123I radioisotopes for medicine.

Alexei was in charge of the “Exotic nuclei school “. His former students include a dozen doctors and candidates of sciences and one corresponding member of the Russian Academy of Sciences. He has supervised ten candidate dissertations. His ex-pupils are employees at cyclotron laboratories in Tashkent, Alma-Ata, and Tomsk. He was engaged in teaching activities at MEPhI, served as a member of the Scientific Council of the National Research Center “Kurchatov Institute”, and was a member of the dissertation council at Kurchatov and the Institute of Nuclear Physics of the Moscow State University. He was a member of the program advisory committees of many laboratories and international conferences. He represented Russia in the IUPAP (International Union
of Pure and Applied Physics) nuclear physics commissions and the OECD Megascience Forum.

In 2003, Alexei was among the handful of leaders of major Russian experiments with a citation index of over 500. His work has received wide recognition; he delivered numerous invited talks at the major international conferences on nuclear physics. He was the author of many monographs and review papers published in Russian and international
journals. Alexei was actively working till the last days of his life. Several of his recent publications are among his most significant ones. He initiated and was an active member of collaborations with institutes in Dubna, Kiev, Alma-Ata, Germany, Japan, and Finland.

His awards included multiple Russian government medals (1966, 1970, 1997, 1998, 2010, 2016), the Badge of Honour and a medal for the 100th anniversary of V. I. Lenin. Alexei was a laureate of the gold medal awarded by the Kurchatov Institute of the Russian Academy of Sciences, the international GN Flerov JINR prize, the 65th-anniversary medal of the Russian nuclear industry, a medal of merits in the development of atomic energy, laureate of 9 Kurchatov Awards, bearer of honour certificates from the nuclear power industry.

Farewell to Alexei Alekseevich Ogloblin will take place on 26 February 2021 at 11.45 in the morgue of hospital No. 67 at st. Salyama Adil, building 2/44.

Dr. Akito Arima has passed away

Dr. Akito Arima has passed away on December 6, 2020 at the age of 90. We would like to
express our sincere condolences to his family and friends. He will be missed by all who
knew him. It would not be an exaggeration to say that during his term as President of
RIKEN, Dr. Arima had built the foundation for the RIKEN Nishina Center of today with
his tremendous support and contribution in budgeting for the RIBF, opening of the RIKEN
Facility Office at RAL and RIKEN BNL Research Center.

Dr. Arima had made numerus outstanding achievements in theory of nuclear structure
physics. Not only was this limited to configuration mixing theory and cluster model but
by proposing and developing “Interacting Boson Model”, he had succeeded in unifiedly
describing collective motions such as nuclear oscillation and deformation.

With these exceptional achievements, Dr. Arima won numerous prestigious awards both domestic
and international including the Nishina Memorial Prize, Japan’s Order of Culture, Tom
W. Bonner Prize in Nuclear Physics from American Physical Society, and Legion of Honor
from France. We will continue to honor his legacy by stepping up our research　activity
to the next level.

Hiroyoshi Sakurai
Director of the RIKEN Nishina Center for Accelerator-Based Science

Predictions for over a thousand of the heaviest atomic nuclei

Physicists from the National Center for Nuclear Research and the University of Zielona Góra have determined and reported extremely important parameters for over 1,300 nuclei, including the nuclei of super-heavy elements, which have not been produced in laboratories so far. These results have just been published in the primary reference journal of nuclear physics: Atomic Data and Nuclear Data Tables.

Scientists in many centers around the world are constantly striving to create and research new elements and their isotopes. The main aim of this international race is to discover the still mysterious forces binding atomic nuclei. The research focuses simultaneously on experimental work using powerful accelerators and detectors, as well as on theoretical calculations to identify the most promising production procedure and propose models that can be verified by experiments. Polish scientists have been specializing in this type of theoretical research for several decades, being world leaders, which is clearly confirmed by the extremely extensive and complete work that has just been presented.

Three Polish scientists: Dr. Piotr Jachimowicz from the University of Zielona Góra and Michał Kowal and Janusz Skalski, professors at the National Center for Nuclear Research (NCBJ) estimated the key parameters for 1,305 heavy and super-heavy nuclei in the atomic number Z from 98 to 126 (and therefore also for elements still undiscovered) and for the number of neutrons N from 134 to 192.

“For our calculations, we used a multidimensional microscopic-macroscopic model that allows us to determine the binding energy of atomic nuclei” – explains Dr. Piotr Jachimowicz from the University of Zielona Góra. “For basic states and the so-called saddle points, we have determined such parameters as: nuclear masses, macroscopic energies, shell corrections and nuclear deformations – that is, the shapes of the nuclei in the ground state and in the saddle point. From them we deduced the energies of alpha decay between the ground states, the energies of the separation of one and two nucleons and the static, adiabatic heights of the fission barriers. ”

“Systematic calculations for odd nuclei, especially their cleavage barriers, are very rare – our work fills this gap” – adds Prof. Michał Kowal, Head of the NCBJ Theoretical Physics Department. “For systems with an odd number of protons, neutrons or both, we used the standard blocking BCS method. We could find the ground-state shapes and energies by minimizing seven axially symmetric strains. We searched for saddle points using the so-called “sinking” in three consecutive stages, using multidimensional deformation spaces, which involved the need to generate giant networks simulating various nuclear shapes. For this purpose, we used our supercomputer in the IT Center in Świerk for the calculations. ”

Some of the results obtained by the researchers concern parameters already known in the experiment and agree very well with these data. This confirms the correctness of the analysis carried out and allows us to believe that the determined values ​​of previously unknown parameters are reliable.

The researchers emphasize that they managed to create one of the most complete data sets available “on the market”, necessary for the analysis of cross sections, i.e. the production probabilities of super-heavy nuclei in individual synthesis channels. “The accuracy of reproducing the masses and other values ​​determined in the area analysed by us is one of the best existing estimates” – adds Prof. Janusz Skalski. “Our use of five- and seven-dimensional deformation spaces represents a significant improvement over other calculations performed so far. Our analysis is also one of the few that takes into account the odd nucleus, usually overlooked due to the difficulty of treating the odd nucleon.”

It is no coincidence that the results will go to the annals of Atomic Data and Nuclear Data Tables. Their importance is not limited to experiments aimed at creating new nuclides. “We have determined parameters, the knowledge of which may also be important for other areas of research” – explains Dr. Michał Kowal. “Among other things, we determined properties for the actinide nuclei, important from the point of view of reactor physics. Parameters determined and given in the paper can be used in astrophysical analyses and predictions concerning nucleosynthesis at particular stages of the universe’s evolution.”

P. Jachimowicz, M. Kowal, J. Skalski

Properties of heaviest nuclei with 98 ≤ Z ≤ 126 and 134 ≤ N ≤ 192,  

Atomic Data and Nuclear Data Tables
(Available online 19 December 2020, 101393, in press).

https://doi.org/10.1016/j.adt.2020.101393

Until February 7, 2020, the work is available online at https://authors.elsevier.com/a/1cGMz,26poewBO; later it will be available in print and for journal subscribers only.

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