Gurgen Muradyan

• Yerevan State University

The cross sections for radiative capture and fission for 236U in the neutron energy ranges 1–2000 eV and 1–1000 eV, respectively, have been measured. The measurements were performed on a flight baseline 5.2 m of the FAKEL linear electron accelerator at the National Research Center Kurchatov Institute using a method based on measuring the distributi...

Prompt and delayed neutrons and secondary γ rays are the informational radiation in the photonuclear technology for recording fissile materials. Due to the high cost of detectors and difficulties in their placing around a container, it is desirable that the same detectors be used to record all kinds of informational radiation. The design of a multi...

The purpose of the present work is to investigate numerically the energy-time characteristics of γ and neutron radiation emitted from strongly screened fissile substances irradiated by pulsed bremsstrahlung. It is shown that when fissile materials are screened by a metal with a small or medium atomic number (e.g., aluminum and iron) the prompt and...

Mathematical modeling of the neutron-resonance method analyzing the elemental and isotopic of matter is performed. The method is based on investigation of γ cascades, emitted by nuclei as a result of the radiative capture of neutrons. Gamma cascades of the determined element (effect) and elements of the matrix (background) are modeled and these cas...

A target of the ″Fakel″ electron linear accelerator is described. The target is a neutron source for neutron spectrometric investigations performed by the time-of-flight method in the wide energy interval from thermal one to some MeV. Neutrons are produced in the photonuclear reaction induced in the target by bremsstrahlung which is produced in the...

The neutron-capture and -scattering measurements and gamma-cascade investigations for 238U resonances have been carried out to study the nature of 238U neutron resonances with anomalously large fission width. Radiation widths for 721.58 eV and 1211.4 eV resonances have been determined. One and the same radiation-width value of the 1211 eV resonance...

In order to measure neutron capture self-indication in the neutron energy range up to 200 keV, a setup based on a 16-section NaI(Tl) scintillation gamma detector has been created at the 500-m flight path of the IBR-30 booster (JINR-Dubna). The detector has a geometric efficiency of 80% and a total scintillator volume of 36 1. The capture self-indic...

The measurements of neutron capture and scattering for 238U have been performed in order to search and investigate neutron resonances with unusual properties. Resonance widths have been determined. For 721 eV resonance from capture data an anomalously low value of radiation width of Гδ=3.2±0.5 meV was obtained, which qualitatively conforms with the...

The paper describes a multisection 4π scintillation detector that is designed for neutron studies by multiplicity spectrometry and is based on NaI(Tl) crystals and a scintillating converter (n, γ) that contains a neutron absorber. It is shown that the use of a scintillating converter increases the registration efficiency and the quality of separati...

Alpha, equal to the ratio of the radiative-capture cross section of a neutron to the fission cross section, is one of the basic constants necessary for the optimization of reactors. In this paper the method of multiplicity spectroscopy was used to perform absolute measurements of alpha for plutonium 239 for allowed resonances in the neutron energy...

The multiplicity spectrometry technique of secondary emission of nuclei excited by thermal neutrons for the neutron cross sections measurements is developed. A multisectional NaI(Tl) scintillation detector for gamma-ray detection with high efficiency and 4pi-geometry is used. The experiments are performed on a stationary 2 MW research reactor by th...

A procedure for measuring neutron cross sections and their ratios based on the multiplicity spectrometry of gamma quanta and neutrons emitted by excited nuclei is considered. Multiplicity spectrometers are described, and their functional characteristics are presented. Results of the radiative capture of fissile nuclei and highly precise alpha value...

An absolute measurement of the alpha value at the Uranium-235 resonances has been performed. For most resonances the accuracy is better than 2% which considerably exceeds that of the available alpha values.

In order to measure the neutron-physical constants with high accuracy and to investigate ways of formation and decay of excited nuclei a method has been developed at the I.V. Kurchatov AEI, based on the gamma-quanta and neutrons multiplicity spectrometry. During 1974-1978 there have been constructed a number of multisectional 4..pi..-detectors whic...

Level parameters were identified, and power functions for Zr⁹°, Zr/; sup 91/, Zr⁹², Zr⁹⁴, and Zr⁹⁶, were found t o be 0.85 plus or ; minus tively. The data are in agreement with optical model predictions. ; (R.V.J.);

We report measurements of the ratio of the probability of spontaneous emission of muons and/or charged pions from ²⁵²Cf to the probability of spontaneous fission of ths nucleus. It is shown that this ratio is less than 5{center dot}10⁻⁸.