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Gorenstein M.I.,NASU Bogolyubov Institute for Theoretical Physics | Gorenstein M.I.,Frankfurt Institute for Advanced Studies | Greiner W.,Frankfurt Institute for Advanced Studies | Rustamov A.,Goethe University Frankfurt | Rustamov A.,Institute of Radiation Problems
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

Within the statistical model, the net strangeness conservation and incomplete total strangeness equilibration lead to the suppression of strange particle multiplicities. Furthermore, suppression effects appear to be stronger in small systems. By treating the production of strangeness within the canonical ensemble formulation we developed a simple model which allows to predict the excitation function of K +/π + ratio in nucleus-nucleus collisions. In doing so we assumed that different values of K +/π +, measured in p + p and Pb + Pb interactions at the same collision energy per nucleon, are driven by the finite size effects only. These predictions may serve as a baseline for experimental results from NA61/SHINE at the CERN SPS and the future CBM experiment at FAIR. © 2014 The Authors.

Mamedov N.A.,University of Massachusetts Amherst | Rzayev A.A.,Institute of Radiation Problems | Shamilov E.N.,Institute of Radiation Problems | Abdullaev A.S.,Institute of Radiation Problems | And 2 more authors.
Acta Horticulturae | Year: 2011

Exposure to radiation has significantly increased during the past hundred years with the development and use of x-rays and radio-isotopes in medicine and through environmental pollution from nuclear weapons and power plants. Because radiation can induce mutagenic changes, interfere with the immune system, and lead to the development of cancers, agents that could protect the body from radiation effects would be of great benefit. In this study, aqueous extracts of saffron (Crocus sativus), scholar tree (Sophora japonica), and yarrow (Achillea nobilis) reduced mutagenic effects of gamma-radiation on albino Wistar rats. The most effective radioprotection and anti-mutagenic activity were demonstrated by the saffron extract, which reduced frequency of chromosomal aberrations in bone marrow cells (35.7% at 3 Gy; 17.1% at 5 Gy) and sperm cells (26.9% at 3 Gy; 16.4% at 5 Gy) and restored cell division. Radiation was applied in a gamma-ionization chamber at the Rkhund-20000 facility located at the Institute of Radiation Problems in Baku using an average power of 1.252 rad s -1.

Ahmadov H.I.,Baku State University | Jafarzade S.I.,Institute of Radiation Problems | Qocayeva M.V.,Azerbaijan Academy of Sciences
International Journal of Modern Physics A | Year: 2015

The analytical solution of the modified radial Schrödinger equation for the Hulthén potential is obtained within ordinary quantum mechanics by applying the Nikiforov-Uvarov method and supersymmetric quantum mechanics by applying the shape invariance concept that was introduced by Gendenshtein method by using the improved approximation scheme to the centrifugal potential for arbitrary l states. The energy levels are worked out and the corresponding normalized eigenfunctions are obtained in terms of orthogonal polynomials for arbitrary l states. © 2015 World Scientific Publishing Company.

Ahmadov F.,Joint Institute for Nuclear Research | Abdinov O.,Institute of Physics | Ahmadov G.,Joint Institute for Nuclear Research | Anfimov N.,Joint Institute for Nuclear Research | And 10 more authors.
Physics of Particles and Nuclei Letters | Year: 2013

The main goal of this work is to study the possibility of detecting alpha particles with a micropixel avalanche photodiode (MAPD) in combination with Lutetium Fine Silicate (LFS) scintillators (500 μm thick). The results show that alpha detectors based on the MAPD are expected to be useful in many applications: public security (associated particle imaging for explosives and drugs detection), radioactive contamination monitoring in various environments, and detection of charged particles from nuclear reactions. © 2013 Pleiades Publishing, Ltd.

Sadygov Z.,National Nuclear Research Center | Sadygov Z.,Joint Institute for Nuclear Research | Ahmadov F.,National Nuclear Research Center | Khorev S.,Zecotek Photonics Inc. | And 5 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2016

Presented is a new model describing development of the avalanche process in time, taking into account the dynamics of electric field within the depleted region of the diode and the effect of parasitic capacitance shunting individual quenching micro-resistors on device parameters. Simulations show that the effective capacitance of a single pixel, which defines the multiplication factor, is the sum of the pixel capacitance and a parasitic capacitance shunting its quenching micro-resistor. Conclusions obtained as a result of modeling open possibilities of improving the pixel gain in micropixel avalanche photodiodes with high pixel density (or low pixel capacitance). © 2015 Elsevier B.V.

Sadigov A.,National Nuclear Research Center | Ahmadov F.,National Nuclear Research Center | Ahmadov G.,National Nuclear Research Center | Ariffin A.,Zecotek Photonics Inc. | And 6 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2016

A new design and principle of operation of silicon photomultipliers are presented. The new design comprises a semiconductor substrate and an array of independent micro-phototransistors formed on the substrate. Each micro-phototransistor comprises a photosensitive base operating in Geiger mode and an individual micro-emitter covering a small part of the base layer, thereby creating, together with this latter, a micro-transistor. Both micro-emitters and photosensitive base layers are connected with two respective independent metal grids via their individual micro-resistors. The total value of signal gain in the proposed silicon photomultiplier is a result of both the avalanche gain in the base layer and the corresponding gain in the micro-transistor. The main goals of the new design are: significantly lower both optical crosstalk and after-pulse effects at high signal amplification, improve speed of single photoelectron pulse formation, and significantly reduce the device capacitance. © 2015 Elsevier B.V.

Pepelyshev Y.N.,Joint Institute for Nuclear Research | Taiybov L.A.,Joint Institute for Nuclear Research | Garibov A.A.,Institute of Radiation Problems | Mekhtiyeva R.N.,Institute of Radiation Problems
Atomic Energy | Year: 2013

The results of an experimental study of the stochastic fluctuations of the energy of IBR-2M pulses, which are used to obtain some parameters of the reactor kinetics, are presented. A pulse energy sequence was recorded at different average power levels and the distribution parameters were calculated. An ionization chamber, placed near the core, with boron was used as the neutron detector. The results obtained made it possible to evaluate the following: the average lifetime of prompt neutrons τ= (6.5 ± 0.2)·10 -8 sec, the absolute power of the reactor and the source of spontaneous-fission neutrons S sp ≤ (6.72 ± 0.12)·106 sec-1. It is shown that the experimental results are close to the computational results. © 2013 Springer Science+Business Media New York.

Jafarov Y.D.,Institute of Radiation Problems
Problems of Atomic Science and Technology | Year: 2011

The radiolysis process of water (liquid phase) under the impact of low - energy electrons (E = 1, 2:5, 5, 10 keV) was mathematically modeled using Monte-Carlo, single collision and pacing methods on the base of Mathcad program. The radiation-chemical yields of the physical (single ionized molecular orbitals- H 2O + 2 (1a1, 2a1, 1b2, 3a1, 1b1), e - sub electron - lost its energy up to a primary electron - excited energy and electron-excited states: H 2O*(A 1B 1, B 1A 1, Rydberg state, diffusion band, dissociative excitation and plasmon-H 2O**) and physicochemical (OH, e - aq, H, H 3O +, H 2, H 2O 2, O 2, OH -, O - 2, HO - 2) phase products of the non-elastic collision of electrons and water molecules were determined.

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