In the wake of the departed

Sergey Tyutyunnikov 21.06.1947 - 05.11.2025

On 5 November, a distinguished physicist, Doctor of Engineering Sciences and Head of Department No.5 of Scientific, Methodological Research and Innovation at the JINR Laboratory of High Energy Physics Sergey Ivanovich Tyutyunnikov passed away.

S.I.Tyutyunnikov had worked at JINR since 1970 after having graduated from Voronezh State University. He started his career at the JINR Laboratory of Nuclear Reactions and since 1972, he had worked in the Department of New Acceleration Techniques. He rose through the ranks from a senior laboratory assistant to the head of a major scientific and methodological department at VBLHEP. From 2007 to 2008, he was VBLHEP Deputy Director for Research.

Early in his career, Sergey Ivanovich was actively involved in the development of the first prototype of a collective accelerator, a prototype of a collective heavy ion accelerator and of the KUTI-20 accelerator. As part of this work, he proposed and developed unique techniques and equipment for diagnosing electron-ion ring bunches, enabling the production of electron rings with design parameters and registering of heavy ion acceleration processes. These results were the basis of his thesis for the degree of Candidate of Physical and Mathematical Sciences, defended in 1987.

During the next stage of his scientific career, S.I.Tyutyunnikov carried out a large series of investigations on the fundamental properties of new superconducting materials using synchrotron radiation beams and an infrared spectrometer he had developed. Based on these investigations, he defended his thesis for the degree of Doctor of Engineering Sciences in 1999.

Together with Professor V.L.Aksenov, S.I.Tyutyunnikov initiated the development of a unique experimental facility - an EXAFS spectrometer. Since May 2007, it has been successfully used in synchrotron radiation beamlines at the Kurchatov Institute National Research Centre for X-ray spectroscopy research. Currently, the energy-dispersive EXAFS spectrometer is one of the best in its class and it is used for research within government programmes.

For a long time, Sergey Ivanovich was engaged in spent nuclear fuel issues and was the leader of the project "Subcritical reactor with accelerator drive" (E&T). From 2010 to 2017, the E&T collaboration obtained unique results that were included in the IAEA database. More than 60 papers have been published based on the research in this area and eight PhD theses and a doctoral thesis have been defended. The work of the E&T collaboration has been included by the IAEA in the international research programme on ADS systems.

In 2014, a department for the development of silicon track systems was established within the VBLHEP Division of Scientific, Methodological Research and Innovation. S.I.Tyutyunnikov dedicated considerable efforts to its work.

S.I.Tyutyunnikov is the author and co-author of over 170 scientific papers and a winner of three JINR prizes. From 1999 to 2016, he taught at the Moscow State University Institute of Nuclear Physics. He supervised three PhD theses, was a member of the JINR Dissertation Council in Nuclear Physics and a member of the Dissertation Council of the Budker Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences.

For his scientific achievements, S.I.Tyutyunnikov was awarded the departmental distinction "Veteran of Nuclear Energy and Industry" in 2002. In 2006, he was awarded the title of "Honorary Employee of JINR" and presented with the Certificate of Honor of the Belarusian Republican Foundation for Fundamental Research and the Certificate of Honor of the Mayor of Dubna. In 2011, he was presented with a letter of gratitude from Rosatom, in 2013 - with the Certificate of Honor of the Governor of the Moscow Region and in 2016, he was awarded the Certificate of Honor of JINR. In 1997, S.I.Tyutyunnikov was awarded the Medal "In Memory of the 850th Anniversary of Moscow" and in 2023, for his contribution to the development of science and strengthening international cooperation, he received gratitude from the Council of Deputies of the Dubna Urban District.

S.I.Tyutyunnikov was a talented scientist, the head of a large staff, actively involved in scientific and public life and enjoyed well-deserved respect and authority among the Institute's staff. He was a kind, considerate and responsive person.

The bright memory of Sergey Ivanovich will forever live in our hearts.

JINR Directorate and VBLHEP staff