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The photonuclear processes department

Head of department - Doctor of physical and mathematical sciences, Prof. Maslyuk Volodymyr Trokhymovych.

Employees: – leading research associate, Doctors of Science V.M. Simulik, senior research associates: Doctors of Science, Laureate of the State Prize of Ukraine in the field of science and technology V.M. Mazur and Laureate of the NAS of Ukraine named I. Pulia A.A. Borovik, Candidates of Science: O.O. Parlag, O.I. Lendyel, M.I. Romaniuk, O.M. Pop and N.I. Svatiuk, Chief engineer of microtron M-30 Y.Y. Haynish, leading engineers: G.F. Pitchenko, Z.M. Bihan, M.V. Hoszowski, O.M. Turhovskyy, I.G. Mehela, I.V. Pylypchynets and P.S. Derechkey, first category technician I.M. Kushtan and worker M.V. Hondorchyn.

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Department of Photonuclear Process is the first academic center for physics in Transcarpathia. It was created in September 1969 as a division of the Institute of Physics USSR of Academy of Sciences. From 1970 to 1982, he was a member of the Institute of Nuclear Research, USSR of Academy of Sciences, from 1982 to 1992 – to Uzhgorod branch INR USSR. It is the largest department of the institute, which by its specificity, is located separately from the main building in the picturesque city of Uzhhorod.

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Now Uzhgorod is well known as the nuclear center of Ukraine involved in fundamental and applied research in nuclear physics.

Experimental basis

The basic nuclear physical apparatus of our department, the M-30 microtron, is mounted in the special laboratory premises (800 м2 total area) with the 2.9 ha sanitary-protective zone. An M-30 microtron provides the possibility to change the accelerated electron energy smoothly within the 1–25 MeV range at the 0.02% energy spread and up to 50 μA electron current. Such parameters allow one to produce the intense fields of the electron, ϒ, and neutron radiation aimed at studying the fundamental and applied nuclear physics problems.

Our parameters:

  • number of M-30 orbits 29;
  • maximal value of the electron beam average current of M-30 - 10 to 50 μA, depending on their energy;
  • output yield - 80 to 100%, radiation pulse duration - 0.2 to 0.3 μs;
  • pulse repetition frequency - 2 kHz.

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Gamma-spectrometric measurements are carried out with the use of high-resolution semiconductor HPGe - detector (150 см3 volume) operating at the liquid nitrogen temperature. The apparatus spectra are processed by a single-board "SBS-40" spectrometer interfaced with the "Pentium" IBM PC with the database including more than 360 isotopes for the 45–5000 кеV energy range.

Principal achievements in the field of fundamental nuclear physical studies:
  • The photo-neutron reaction cross sections and yield for the wide class of nuclei ranging from scandium to rhenium have been obtained. The fine structure of the time distributions of delayed neutrons has been studied for the 232Th, 235,238U, 237Np, 239Pu , 241Am nuclei.
  • Within the 4–12 MeV energy range the cross-sections for inelastic gamma-quanta scattering with excitation of isomer states in the 77Se, 79Br, 87Sr, 111Cd, 113In, 138Ba, 167Er, 179Hf, 183W, 191Ir, 195Pt, 199Hg nuclei have been measured allowing one to determine the isomer ratio dependences on nuclei mass, gamma-quanta energy as well as the difference ΔJ of the ground Jg and isomer Jm states.
  • The excitation cross sections for the isomer states of the 44Sc, 73,77,79,81Se, 84,86Rb, 85,87Sr, 89Zr, 91Mo,109Pd, 112In, 133.135.137Ba, 141Nd, 143Sm, 152Eu, 164Ho, 167Er, 179Hf, 183W, 184Re, 197Hg, 199mHg nuclei in the photo-neutron reactions in the energy range 8-18 MeV have been obtained for the first time. The experimental isomer ratios of the yields and cross-sections for the above nuclei have also been determined. The shell effects in the behavior of isomer ratios have been found while filling up the shells with the N=50 and N=82 neutron numbers.
  • At the photo-fission from the 232Th, 234,235,238U, 237Np, 239,240Pu targets the cumulative Kr-85, Kr-87, Kr-88, Y-91, Sr-91, Y-92, Nb-97, Zr-97, Tc-99, Ru-105, Ag-112, Sb-129, I-131, I-132, Te-132, I-133, I-134, I-135, Xe-135, Ba-139, La-142 yields have been measured.

Principal achievements in the field of applied nuclear physical studies:
  • Among the achievements in this field, one should mention the creation of the electronic atlas (for more than 106 spectra) of apparatus gamma-spectra of rare-earth, noble, and scattered chemical elements activated by Bremsstrahlung gamma- and neutron radiation.
  • The neutron- and gamma-activation techniques have been applied for the first time to control the chemical purity of the initial materials, the stoichiometry of complex materials, and identify their microelement composition with the use of the M30 microtron at the 18 MeV electron energy. In particular, for certain chemical elements, the sensitivity of the neutron-activation method reaches 10-6 mass%.
  • The modes of modification of the semiconductors/dielectrics parameters by irradiating them with the boundary dozes (up to 1017–1018 electrons/сm2) of high-energy (1–25 MeV) electrons and Bremsstrahlung have seen developed. There are directed changes to structural, electrophysical, magnetic, and optical properties, including radiation coloring of optical materials, among these capabilities. The character of variation of parameters depending on the irradiation conditions has been studied.

Medical and biological achievements:
  • The systematic works on the ecological monitoring of heavy and gamma-active nuclides have been started in Transcarpathia. The objects of the studies are the samples of sols and water taken from the different water basins of the Ukrainian and Slovak Carpathian areas. The sorption ability of heavy metals by Transcarpathian zeolites are being studied, the noble metal content in the gold-carrying ores in Transcarpathia is under investigation.
  • In the field of nuclear medicine, there exists a possibility to produce the short-lived radionuclides for the PED-computer diagnostics and radioisotope therapy purposes. The radiation immunology studies for treating the complicated diseases related to the immunodeficient and oncology are being carried out.
  • It is promising to obtain new data on the technical modes of radiative oil cracking to increase the depth of oil processing, extract heavy and noble metals, and reduce the energy capacity of oil product transportation.

In 2002 the M-30 microtron IEF NAS of Ukraine entered into the registry objects of national property of Ukraine. He is also listed in the directory of nuclear physics installations IAEA.

The scientists of department cooperating with the Institute of Nuclear Physics of University of Lyon (France), University of Padua (Italy), Institute of Applied Physics, Bucharest (Romania), Technical University, Prague (Czech Republic), Institute of Solid State Physics, Sofia (Bulgaria).

In particular, the Department is a party to the cooperation agreements with the Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, with the Institute of Radiochemistry and Radioecology of the University of Pannonia, Veszprém, Hungary, the Institute of Experimental Physics of the Slovak Academy of Sciences, Kosice, Slovakia. The scientists of Department cooperate with the Technical University, Prague (Czech Republic), Institute of Solid State Physics, Sofia (Bulgaria), and have the joint research with colleagues of the Institute of Nuclear Research of the Polish Academy of Sciences, Krakow by using the M-30 microtron on field of tissue-equivalent dosimetry.

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