International conference
Resonance phenomena in atomic systems
(to the 85th anniversary of Academician Otto Shpenik)

July 14, 2023 is the 85th anniversary of Otto B. Shpenik, a known Ukrainian scientist, a top specialist in physics of electron and atomic collisions, one of the founders of the scientific school in atomic physics in Ukraine, the first director of the Institute of Electron Physics of the National Academy of Sciences of Ukraine, academician of the National Academy of Sciences of Ukraine, a foreign member of Hungarian Academy of Sciences.

Otto Shpenik was born on July 14, 1938 in Mukachevo. In 1955 he graduated from a secondary school, in 1956-1961 he was a student and from 1961 till 1964 – a post-graduate (Ph. D.) student at the Department of Optics, Faculty of Physics and Mathematics of Uzhhorod State University. In 1966 he defended his Ph. D. degree in Leningrad State University and in 1975 he accomplished his Dr. Sc. degree in the Institute of Physics of the Academy of Sciences of Ukraine. From 1982 till 1988 he was the head of Department of Ionic Processes at Uzhhorod Branch of the Institute of Nuclear Research of the Academy of Sciences of Ukraine, from 1988 till 1992 he was the head of this branch and a vice director of the Institute of Nuclear Research of the Academy of Sciences of Ukraine. From 1992 till 2017 he was the director of the Institute of Electron Physics of the National Academy of Sciences of Ukraine.

Diverse results of scientific research performed by O.B. Shpenik belong to the achievements of the world science in the field of experimental physics, optics, physics of electron and atomic collisions, physical electronics, interaction of electrons with surface. He is rightfully considered one of the founders of precise experiments with highly monoenergetic electron beams which enabled fine (resonance) structure in the electron-impact excitation functions of atoms to be discovered. Under his supervision modern experimental equipment was developed, a number of original devices were created: electron guns with different parameters, multichannel electron and molecular beam sources, a universal effective ion source. He was the first to develop and make highly efficient monochromators and analysers of electrons with highest parameters including a 127-degree cylindrical electrostaticmonochromator, trochoidal and hypocycloidal electron spectrometers with helical trajectories, vacuum microscales, vibrational neutral-beam choppers. O.B. Shpenik developed many unique experimental methods including the method of determination of absolute cross-sections of total scattering of electrons by atoms and molecules (electron trap method), quadrupole capacitor method to measure resonance and off-resonance recharge of ions by atoms, metastable spectroscopy method, method of electron backscattering from atoms, molecules, ions, and solid surfaces.

O.B. Shpenik showed a particular research interest to precise experiments on highly monoenergetic electron beam interaction with atoms and molecules. These experiments enabled first studies of the resonant character of excitation of energy levels of atoms close to the process threshold to be carried out, the fine structure of the energy dependences of excitation cross-sections of atoms to be studied in detail, the dominant role of negative ions in the formation of atomic level "resonances" to be unambiguously proven. This led to a new trend in atomic physics – negative ion spectroscopy. Studies performed by the group of Prof. Shpenik were the first to discover the effect of interaction of the scattered and the ejected electrons in the ion core field (postcollisional interaction effect) which occurs at electron-atomic collisions when the electron energies are close to the energies of autoionizing states of the atoms. This effect results in an oscillation-type structure in the energy dependences.

O. B. Shpenik essentially contributed to the studies of processes of slow electron-atom and electron-molecule collisions. For these processes a regular oscillation-type structure in the energy dependences of alkaline-earth ion resonance recharge was determined. An effect of phase interference of quasimolecular terms was revealed which can be observed only at the polarization of optical radiation induced by heavy particle collisions. New interesting results were obtained regarding the dynamics of excitations and emerging of metastable states, emission of thin films under low-energy electrons and at scattering of ultamonoenergetic electrons by thin films and solid surfaces. These experiments can be considered a discovery and a turning point in the studies of physical properties of atoms and molecules.

Broad international recognition of O.B. Shpenik is revealed in the fact that he was the first Ukrainian scientist to be elected a member of the General Committee of International Conferences of Physics of Electron, Photon and Atomic Collisions. He was a chairman of organizing committees at many international conferences, a member of the International Council of Hungarian Professors, is rated high as a scientist beyond Ukraine. A vivid evidence for this is the comment on the achievements of O.B. Shpenik and his colleagues by Prof. F.H. Reed from the University of Manchester (the United Kingdom), a member of the Royal Society: "The physicists from Uzhhorod improved and created original equipment and methods of studies of elementary collision processes, discovered a number of effects in atomic physics. Their achievements are well known and recognised internationally and the results are published in top journals, highly cited and discused in a number of reviews and monographs".

The conference will be held on September 19-21, 2023