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Shumakov A.V.,Dukhov All Russia Research Institute of Automatics VNIIA
Atomic Energy

A method is proposed for determining the detection threshold of radiation monitors, using a radiation source with arbitrary flux, activity or mass of nuclear material. Good agreement is shown between the detection threshold of several neutron radiation monitors, determined using 244Cm and 252Cf sources with different fission-neutron fluxes. An example of converting the detection threshold measured by the proposed method or the number of detections with different background to other conditions is presented. © 2013 Springer Science+Business Media New York. Source

Kolomiytsev G.V.,National Research Nuclear University MEPhI | Igashov S.Y.,Dukhov All Russia Research Institute of Automatics VNIIA | Urin M.H.,National Research Nuclear University MEPhI
Physics of Atomic Nuclei

The Green’s function method is used to formulate the single-quasiparticle dispersive optical model with the aim of semimicroscopically describing the relaxation of deep hole states in medium-heavy-mass spherical nuclei. The results of the calculations performed on the basis of this model for the 208Pb parent nucleus are compared with experimental data. © 2014, Pleiades Publishing, Ltd. Source

Syromukov S.V.,Dukhov All Russia Research Institute of Automatics VNIIA
Atomic Energy

It was important to determine the effect of the chemical composition of the target and the main parameters of a tube, such as the accelerating voltage, ion current, and the atomic-molecular and isotopic composition of the ion beam, on the sputtering. The SRIM code intended for modeling the motion of ions in matter was used to calculate the sputtering yield and ion range. It was observed that sputtering rate increased because more atoms interact with the target and their energy decreased when using molecular ions. The sputtering rate was proportional to the ion flux density on target and the sputtering yield and inversely proportional to the particle concentration in the target. It also depended on the atomic-molecular and isotopic compositions of the ion beam. Source

Shumakov A.V.,Dukhov All Russia Research Institute of Automatics VNIIA
Atomic Energy

The results of an investigation of the effect of the number of local detectors in stationary radiation monitors and their count combinations (criteria) on the detection threshold assuming an equally probable distribution of the radioactive material in the controlled space are presented. A parameter is proposed for making quantitative comparisons of the effectiveness of the same radiation monitor with a different number of detectors, criteria and background is proposed. © 2013 Springer Science+Business Media New York. Source

Chernikova D.,Chalmers University of Technology | Romodanov V.L.,National Research Nuclear University MEPhI | Belevitin A.G.,National Research Nuclear University MEPhI | Afanasev V.V.,National Research Nuclear University MEPhI | And 6 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

The present paper discusses results of full-scale experimental and numerical investigations of influence of construction materials of portable pulsed neutron generators ING-031, ING-07, ING-06 and ING-10-20-120 (VNIIA, Russia) to their radiation characteristics formed during and after an operation (shutdown period). In particular, it is shown that an original monoenergetic isotropic angular distribution of neutrons emitted by TiT target changes into the significantly anisotropic angular distribution with a broad energy spectrum stretching to the thermal region. Along with the low-energetic neutron part, a significant amount of photons appears during the operation of generators. In the pulse mode of operation of neutron generator, a presence of the construction materials leads to the "tailing" of the original neutron pulse and the appearance of an accompanying photon pulse at ~3ns after the instant neutron pulse. In addition to that, reactions of neutron capture and inelastic scattering lead to the creation of radioactive nuclides, such as 58Co, 62Cu, 64Cu and 18F, which form the so-called activation radiation. Thus, the selection of a portable neutron generator for a particular type of application has to be done considering radiation characteristics of the generator itself. This paper will be of interest to users of neutron generators, providing them with valuable information about limitations of a specific generator and with recommendations for improving the design and performance of the generator as a whole. © 2014 Elsevier B.V. Source

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