Low cost scintillation detectors as compared with HPGe detectors are considered to be one of most important radiation detection tools. Therefore, these detectors can be manufactured in different ...shapes and work at room temperature without any cooling systems, which added an extra advantage to it. This work presents a study of a cubic detector with a rectangular cavity in different experimental setup geometries, using standard point-like gamma-ray sources, where the efficiency of the detector in these geometries was the target to be studied. According to this aim, the data from the experimental measurements was used to determine the detector efficiency. An analytical calculation of the detector efficiency was done by using a new mathematical expression, this mathematical expression depends on the efficiency transfer technique and effective solid angle calculations. To support the mathematical model, the source-to-detector arrangement was simulated by Geant4 Monte Carlo code. All the compared efficiency results were found to be promising and trusted based on the calculated deviation percentages.
•Calibration of cubic with rectangular NaI (Tl) detectors using a non-axial radioactive point-like gamma-sources.•New analytical approach and Geant4 simulation were used to calculate the full-energy peak efficiency.•Simulation of photons was modeled mathematically.•The analytical equations and complex integrations were used over the radioactive point sources placed non-axially.•Remarkable agreement between measured, calculated, Geant4 efficiencies were achieved.
The first experiments were carried out to study the elemental composition of archaeological ceramics using prompt gamma activation analysis (PGAA) at the pulsed reactor IBR-2, Frank Laboratory of ...Neutron Physics (FLNP) - Joint Institute for Nuclear Research (JINR). A radiation-resistant n-type High Purity Germanium (HPGe) detector was used to measure the radioactivity. The concentrations of 14 elements were determined namely; Al, C, Ca, Fe, Gd, H, K, Mn, Na, P, S, Si, Sm, and Ti. The obtained results were compared with those analyzed by other analytical techniques INAA (Instrumental Neutron Activation Analysis) and portable X-ray fluorescence (XRF) for the same archaeological batches. The results revealed a good agreement within a range of 1–30%. These insights will contribute to the discussion of improving the PGAA installation and automation of the data obtained, which in turn will improve the quality of analysis and increase the number of determined elements. In this work results are presented, and the analytical merits are compared.
•For the first time, the PGAA facility at reactor IBR-2 – JINR was used in archaeological studies.•The concentrations of 14 elements were determined, including some of light elements.•The data were statistically treated in order to ensure the validity of the facility.•IAEA's intercomparing analysis are highly consistent with the obtained results, except Cd and Hg are outliers.
The new experimental setup has been built at the 11b channel of the IBR-2 research reactor at FLNP, JINR, to study the elemental composition of samples by registration of prompt gamma emission during ...thermal neutron capture. The setup consists of a curved mirror neutron guide and a radiation-resistant HPGe high-purity germanium detector. The detector is surrounded by lead shielding to suppress the natural background gamma level. The sample is placed in a vacuum channel and surrounded by a LiF shield to suppress the gamma background generated by scattered neutrons. This work presents characteristics of the experimental setup. An example of hydrogen concentration determining in a diamond powder made by detonation synthesis is given and on its basis, the sensitivity of the setup is calculated being ∼4 μg.
The IREN complex for neutron physics research was constructed at the Frank Laboratory of Neutron Physics based on a linear accelerator of electrons up to an energy of 50 MeV. Measurements of the ...neutron flux density in a wide range of energies (from thermal to fast) are required in various experiments. This is done by neutron activation analysis with high-resolution gamma spectroscopy. In order to determine the flux of resonant neutrons more accurately, one needs to calculate the effective resonance integrals with specific features of the real neutron spectrum and the thermal motion and absorption of neutrons in the sample taken into account. A program for computation of effective resonance integrals has been developed for this purpose. The effective resonance integrals for
197
Au,
95
Zr,
97
Zr, and
63
Cu are calculated using this program. The values differ considerably from the ones given in reference literature. These results are used to more accurately determine the flux density of neutrons.
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.
A neutron activation analysis (NAA) of three samples of human remains of the 16th and 17th centuries from the necropolises of the Moscow Kremlin has been carried out at FLNP JINR. The samples were ...irradiated at two facilities: the IREN source of resonance neutrons and the IBR-2 reactor. Spectra of the induced activity of the irradiated samples were measured by using the automatic measurement system developed at the Frank Laboratory of Neutron Physics (FLNP) of the Joint Institute for Nuclear Research (JINR). This system consists of a high-purity germanium detector with spectrometric electronics, a sample changer, and control software. Mass fraction of arsenic, mercury, and some other elements were calculated using two NAA methods—relative and absolute. The obtained values confirm the fact of acute mercury poisoning of Anastasia Romanovna, the first wife of Tsar Ivan Vasil’evich the Terrible, the first Russian Tsarina (died in 1560). High levels of mercury were detected in the bone remains of Tsarevich Ivan Ivanovich (died in 1581), the son of Tsar Ivan the Terrible, and Prince Mikhail Vasil’evich Skopin-Shuiskii (died in 1610). The results provide an opportunity to introduce into scientific circulation the exact values of mass fraction of mercury, arsenic, and other elements in the samples taken from the burials of the Russian historical figures of the second half of 16th–early 17th century.
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.
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.
A series of experiments has been conducted at the Frank Laboratory of Neutron Physics (FLNP) of the Joint Institute for Nuclear Research (JINR) in order to study the possibility of determining the ...moisture content of coke using a standard neutron source. The proposed method is based on a measurement of the spectrum of prompt γ rays emitted when samples are irradiated by fast and/or thermal neutrons. The moisture content is determined from the area of the peaks of characteristic γ rays produced in the radiative capture of thermal neutrons by the proton (
E
γ
= 2.223 MeV) and inelastic scattering of fast neutrons by
16
O (E
γ
= 6.109 MeV). The
239
Pu–Be neutron source (〈
E
n
〉 ~ 4.5 MeV) with an intensity of ~5 × 10
6
n/s was used to irradiate the samples under study. A scintillation detector based on a BGO crystal was used to register the characteristic γ radiation from the inelastic fast neutron scattering and slow (thermal) neutron capture. This paper presents the results of humidity measurement in the range of 2–50% 1, 2.
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