In this article, we are presenting the results of model calculations for (
n
,
p
) and (
n
,2
n
) reaction cross sections using the standard nuclear reaction codes TALYS-1.8 and EMPIRE-3.2 for
67,70
...Zn,
92,96,100
Mo and
208
Pb isotopes in neutron energy range 0–20 MeV. Different nuclear level density models and optical model potential available in the codes have been tested for the estimation of cross sections of desired nuclear reactions. Moreover, in this work, the contribution to the cross section from different reaction mechanisms such as compound nucleus process, pre-equilibrium emission and direct reaction is also discussed in detail. The calculated results are compared with the existing experimental data from the IAEA-EXFOR database.
The reaction induced by the inelastic scattering of 14.1-MeV neutrons on chromium nuclei is studied by means of the tagged-neutron method at the TANGRA (TAgged Neutrons and Gamma RAys) facility ...deployed at Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, and based on the ING-27 standard neutron generator. The energies of visible gamma transitions occurring in various reactions of neutron interaction with chromium nuclei and their partial cross sections are determined. The results obtained by measuring the angular distribution of gamma rays for
Cr are analyzed and are compared with respective results of other experimental studies available in the literature.
The results obtained by measuring the angular and energy distributions of gamma rays originating from the inelastic scattering of 14.1-MeV neutrons by carbon and oxygen nuclei are presented. The ...measurements in question were performed by the tagged-neutron method in a beam of an ING-27 standard portable neutron generator. The angular distributions of gamma rays emitted by the 2
+
state of
12
С at 4.43 MeVand the 3
−
state of
16
O at 6.13 MeV were obtained.
Inelastic scattering of 14.1 MeV neutrons on iron Fedorov, N. A.; Grozdanov, D. N.; Kopatch, Yu. N. ...
The European physical journal. A, Hadrons and nuclei,
06/2021, Letnik:
57, Številka:
6
Journal Article
Recenzirano
An investigation of inelastic scattering of 14.1 MeV neutrons on an iron sample was carried out using an improved TANGRA (TAgged Neutron and Gamma RAys) setup at JINR (Dubna). The yields of the ...occurring
γ
-transitions and anisotropy of the emitted
γ
-rays were measured using the tagged neutron method. The setup with a high-purity germanium (HPGe) detector was used to obtain the energy spectrum of
γ
-rays. The setup with 18 BGO scintillation detectors positioned in a circle around the sample was used to obtain angular distributions of
γ
-rays. A detailed
γ
-spectrum for
(
n
,
X
γ
)
reactions was obtained and the
γ
-ray angular distribution was measured for the 847 keV and 1238 keV
γ
-transitions. The distribution was fitted by Legendre polynomials up to fourth order and the angular distribution coefficients
a
2
,
a
4
were extracted. A comparison with other published experimental results is given. Model calculations using computer code TALYS 1.9 were performed. The results of calculations are discussed in comparison with the obtained experimental data.
At present, in the Joint Institute for Nuclear Research (JINR), Dubna, Russia, experiments to study the process of inelastic scattering of fast neutrons with the nuclei of various substances are ...being conducted in the frame of the TANGRA (TAgged Neutron and Gamma RAys) project.
The existing TANGRA facility allows to obtain precise information about the angular and energy distributions of gamma-rays resulting from the inelastic scattering of 14.1 MeV neutrons on complex nuclei.
As source of neutrons, we used a portable neutron generator ING-27 (En=14.1MeV), designed and created by VNIIA (Moscow) with an embedded double-sided 64-pixel silicon (gallium arsenide) alpha-particle detector, by means of which 64 independent tagged neutron beams are formed.
Tagging of neutrons is done by registration of the alpha particle, produced in the binary reaction d + t → (α + n), which is emitted in direction almost opposite to that of the neutron.
To obtain correct information about the characteristics of the process of inelastic neutron scattering on nuclei, it is necessary to know the parameters of all 64 tagged neutron beams with good accuracy.
To solve this problem, we have developed and created a two-coordinate position-sensitive silicon detector of fast neutron (profilometer), by means of which we measured the characteristics of all the 64 tagged neutron beams.
In this paper we give a description of the design of the profilometer and present the results from the measurements of profiles of 64 tagged neutron beams formed by ING-27.
Gamma-ray detector systems are important instruments in a broad range of science and new setup are continually developing. The most recent step in the evolution of detectors for nuclear spectroscopy ...is the construction of large arrays of detectors of different forms (for example, conical, pentagonal, hexagonal, etc.) and sizes, where the performance and the efficiency can be increased. In this work, a new direct numerical method (NAM), in an integral form and based on the efficiency transfer (ET) method, is used to calculate the full-energy peak efficiency of a single hexagonal NaI(Tl) detector. The algorithms and the calculations of the effective solid angle ratios for a point (isotropic irradiating) gamma-source situated coaxially at different distances from the detector front-end surface, taking into account the attenuation of the gamma-rays in the detector's material, end-cap and the other materials in-between the gamma-source and the detector, are considered as the core of this (ET) method. The calculated full-energy peak efficiency values by the (NAM) are found to be in a good agreement with the measured experimental data.
The response function of the BGO, NaI (Tl) and LaBr3(Ce) scintillation detectors to monoenergetic gamma quanta was built on the basis of Monte Carlo simulations using the GEANT4 toolkit and ...calibration measurements with gamma radiation sources of different energies. The response function consists of seven components: the first six constitute the detector’s response to a direct hit of monoenergetic gamma radiation and depend on the properties of the detector (size, material, energy resolution, etc.), and the seventh component represents the effect of surrounding materials on the measured gamma spectrum. For each component of the function, the analytical form of the energy dependence is determined and its parameters are found when registering gamma quanta with energies in the range from 0.3 MeV to 10 MeV.
Tagged neutrons with an initial energy of 14.1 MeV scattered on a carbon sample are measured within the framework of the TANGRA project. Angular distributions of neutrons are obtained for elastic ...scattering and scattering to the first excited state of
12
C with an energy of 4.44 MeV. Results are compared to experimental data from other authors and model calculations performed using a coupled channels model with a deformed optical potential.
Tagged neutrons are used to perform an experimental investigation of the inelastic scattering of 14.1 MeV neutrons on
23
Na and
35
Cl nuclei as part of the TANGRA project at the Frank Laboratory of ...Neutron Physics, Joint Institute for Nuclear Research. The energies and yields of γ quanta for transitions observed in the experiment are measured, and the γ angular distribution coefficients for the highest intensity γ transitions are obtained. The experimental data are compared to others in the literature.
The TALYS 1.9 program is used to calculate cross sections of processes that occur during the scattering of fast neutrons on
48
Ti,
52
Cr, and
56
Fe isotopes. Results from model calculations are ...compared to data obtained in the TANGRA project using tagged neutrons from the yields of γ-quanta for Ti, Cr, and Fe isotopes, and the results from earlier experiments. Analysis of the model description’s sensitivity to the choice of the direct reaction mechanism shows the most informative characteristic from this viewpoint is the differential cross section of inelastic scattering.
