scholarly journals Prompt and delayed gamma rays induced by epithermal and fast neutrons with indium

2021 ◽  
Author(s):  
Eric Mauerhofer ◽  
Zeljko Ilic ◽  
Christian Stieghorst ◽  
Zsolt Révay ◽  
Matthias Rossbach ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Spectrum ◽  
Gamma Rays ◽  
Cross Sections ◽  
Partial Cross Section ◽  
Fast Neutrons ◽  
Prompt Gamma ◽  
Activation Products ◽  
Average Neutron ◽  
Average Neutron Energy

AbstractThe emission of prompt and delayed gamma rays from (n,γ) and (n,n´γ) reactions induced by irradiation of indium with epithermal and fast neutrons was investigated with the instrument FaNGaS operated at Heinz-Maier-Leibnitz Zentrum (MLZ) in Garching. The average neutron energy of the neutron spectrum was 2.30 MeV. The measurement was done at an angle of 90° between neutron beam and detector. A total of 136 prompt gamma lines from which 42 are related to the capture of epithermal and fast neutrons and 94 to the inelastic scattering of fast neutrons were detected together with the delayed gamma lines of the activation products 113mIn, 114m2In, 115mIn, 116m2In and 116mIn. Intensities and neutron spectrum averaged isotopic partial cross section of the gamma lines are presented. Additionally the neutron spectrum averaged cross sections of the reactions, 113In(n,n´)113mIn, 113In(n,γ)114m2In, 115In(n,n´)15mIn, 115In(n, γ)116m2In and 115In(n, γ)116mIn were determined from the corresponding delayed gamma rays of the formed isotopes as 143 ± 22, 288 ± 13 194 ± 18, 201 ± 10 and 508 ± 24 mb respectively. The various results obtained were found consistent with the literature data. However, our measurement indicate the need to reevaluate the cross section of the 115In(n,γ)116m2In reaction for thermal neutrons.

Cross section measurements for the reactions of fast neutrons with indium

1976 ◽  
Vol 54 (7) ◽  
pp. 757-765 ◽  
Author(s):  
D. C. Santry ◽  
J. P. Butler
Keyword(s):  
Neutron Flux ◽  
Cross Section ◽  
Neutron Spectrum ◽  
Cross Sections ◽  
Fission Neutron ◽  
Activation Method ◽  
Fast Neutrons ◽  
Fission Neutron Spectrum

Excitation curves for the reactions 115In(n,n′) 115Inm, 113In(n,n′)113Inm, and 115In(n,2n)114Inm have been measured by the activation method. The neutron flux at energies below 5.1 MeV was determined with a calibrated neutron long counter while at higher energies, measurements were made relative to the known cross section for the 32S(n,p) reaction. Effective cross sections for a 235U fission-neutron spectrum calculated from our measured excitation curves are 173 ± 9 mb for 115In(n,n′)115Inm, 123 ± 24 mb for 113In(n,n′)113Inm, and 0.64 ± 0.06 mb for 115In(n,2n)114Inm.

Measurements of the cross-section of 111Cd(n,n′)111mCd reaction for 241Am/Be neutrons

2021 ◽  
pp. 2150084
Author(s):  
G. S. M. Ahmed ◽  
M. Tohamy ◽  
P. Bühler ◽  
M. N. H. Comsan
Keyword(s):  
Cross Section ◽  
Neutron Energy ◽  
Cross Sections ◽  
Detection Efficiency ◽  
Neutron Fluence ◽  
Reaction Products ◽  
The Cross ◽  
Cadmium Target ◽  
Average Neutron ◽  
Average Neutron Energy

The cross-section of the [Formula: see text] reaction was measured with [Formula: see text] neutrons using a natural cadmium target [Formula: see text]. The neutron fluence and mean neutron energy of the source were determined using the ISO 8529-1 neutron spectrum and the known cross-sections of the monitor reaction [Formula: see text]. In order to measure the poor [Formula: see text]-ray activity of the reaction products, an HPGe detector with 70% detection efficiency surrounded by an adequate graded shield was applied. The efficiency calculations for the detector were performed using standard point calibration sources and the EFFTRAN efficiency code. Using the measured values of the neutron flux and the induced [Formula: see text]-ray activity of [Formula: see text], the cross-section of the [Formula: see text] reaction at the average neutron energy of 4.05 MeV was found to be [Formula: see text] mb. An estimation of the contribution to the total cross-section by the accompanied reactions [Formula: see text] and [Formula: see text] was achieved and the related cross-sections were found to be 0.16 mb and 8.99 mb, respectively.

Oxygen K near edge structures studied with multiple scattering calculations

1988 ◽  
Vol 46 ◽  
pp. 504-505
Author(s):  
Xudong Weng ◽  
Peter Rez
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Partial Cross Section ◽  
Energy Window ◽  
Edge Structure ◽  
Fine Structures ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
Quantitative Chemical

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.

Neutron-Gamma Discrimination Using Zero-Crossing Method for BC454 Boron Loaded Plastic Scintillator

2010 ◽  
Author(s):  
Dong Wang ◽  
Bin He ◽  
Quanhu Zhang
Keyword(s):  
Gamma Rays ◽  
Cross Sections ◽  
Plastic Scintillator ◽  
Detection Efficiency ◽  
Discrimination Performance ◽  
Slow Neutron ◽  
Fast Neutrons ◽  
Zero Crossing ◽  
High Detection Efficiency ◽  
Slow Neutrons

Boron loaded plastic scintillator could detect both fast neutrons (thanks to hydrogen) and slow neutrons (thanks to 10B). The large cross sections of both reactions lead to high detection efficiency of incident neutrons. However, gamma rays must be rejected first as the scintillator is also sensitive to them. In the present research zero crossing method was used to test neutron-gamma discrimination performance of BC454 boron loaded plastic scintillator. Three contrast experiments were carried out and different thermalization degrees lead to different time spectra in the MCA. Further analysis proved that three Gaussian curves could be used to fit the spectra; they corresponded to gamma rays, fast neutrons and slow neutrons respectively. The slow neutron curve could be clearly separated from the gamma curve. Discrimination performance for fast neutrons became poor, but their peaks could also be separated.

scholarly journals Analysis of cross sections on iron and oxygen using Cf-252 neutron source

2020 ◽  
Vol 239 ◽  
pp. 18005
Author(s):  
Bohumil Jansky ◽  
Jiri Rejchrt ◽  
Evzen Novak ◽  
Anatoly Blokhin
Keyword(s):  
Cross Section ◽  
Neutron Source ◽  
Neutron Spectrum ◽  
Heavy Water ◽  
Cross Sections ◽  
Energy Region ◽  
Nuclear Data ◽  
Data Section ◽  
Neutron Spectra ◽  
Artificial Changes

The leakage neutron spectra measurements have been done on benchmark spherical assemblies with Cf-252 source in center of 1) heavy water sphere with diameter of 30 cm (with Cd cover) and of 2) iron spheres with diameter of 100 cm and 50 cm. It has been stated for years that transport calculations by iron overestimate measured spectra in energy region around 300 keV by about 20-40 % (calculation to measurement ratio C/E = 1.2-1.4). The influence of an artificial changes in cross-section XS-Fe-56 (n,elastic)designed by IAEA, Nuclear Data Section, has been studied on the iron spheres. Influence of those XS-corrections to calculated neutron spectrum is presented.

scholarly journals CRITICAL EXPERIMENT OF THORIUM LOADED THERMAL CORES AT KUCA (1) A NEW CRITICAL EXPERIMENT OF THORIUM LOADED CORE WITH HARDER NEUTRON SPECTRUM IN KUCA

2021 ◽  
Vol 247 ◽  
pp. 09013
Author(s):  
Tadafumi Sano ◽  
Jun-ichi Hori ◽  
Jeaong Lee ◽  
Yoshiyuki Takahashi ◽  
Kazuki Takahashi ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Spectrum ◽  
Cross Sections ◽  
Capture Cross Section ◽  
The Other ◽  
Capture Cross ◽  
Delayed Neutron ◽  
Integral Evaluation ◽  
Critical Experiment ◽  
The Difference

In order to perform integral evaluation of 232Th capture cross section, a series of critical experiments for thorium-loaded and solid-moderated cores in KUCA had been carried out. In these experimental cores, H/235U nuclide ratio ranged about from 150 to 315, and 232Th/235U nuclide ratio ranged about from 13 to 19. In this study, a new critical experiment with Th loaded core in KUCA, which had about 70 of the H/235U ratio and 12.7 of 232Th/235U ratio, was carried out. As results, the excess reactivity was 0.086 ± 0.003 (% dk/k) and the keff was 1.0009 ± 0.0003, where the effective delayed neutron fraction was 7.656E-3. The keff was also calculated by MVP3.0 with different nuclear libraries. The respective calculations with JENDL-4.0, JENDL-3.3 and ENDF/B-VII.0 lead to 1.0056 ± 0.0086 (%), 1.0048 ± 0.0085 (%) and 1.0056 ± 0.0086 (%).On the other hand, the further MVP3.0 calculations, where only the 232Th cross sections were taken from JENDL-4.0, JENDL-3.3 or ENDF/B-VII.0 but all other nuclides were done from JENDL-4.0, were carried out to examine an impact of the difference of 232Th cross section among these nuclear libraries to the keff. The keff calculated with respective 232Th cross sections from JENDL-3.3 and ENDF/B-VII.0 was 1.0038 ± 0.0086 (%) and 1.0040 ± 0.0086 (%).

scholarly journals Impact of average neutron energy on the fast neutron fluency measurement by Np237 fission to capture ratio and reverse dark current of planar silicon detector methods

2019 ◽  
Vol 204 ◽  
pp. 04002
Author(s):  
M. Szuta ◽  
S. Kilim ◽  
E. Strugalska-Gola ◽  
M. Bielewicz ◽  
N.I. Zamyatin ◽  
...  
Keyword(s):  
Fast Neutron ◽  
Cross Section ◽  
Neutron Energy ◽  
Silicon Detector ◽  
Nuclear Data ◽  
Capture Cross ◽  
Silicon Detectors ◽  
Planar Silicon ◽  
Average Neutron ◽  
Average Neutron Energy

This work is a subsequent step to study the feasibility of fast neutron fluency measurements using two different complementary methods. Np-237 samples and planar silicon detectors were mounted very close to each other on different sections of a subcritical assembly irradiated with the proton beam of 0,66 GeV (the Quinta assembly at the Joint Institute for Nuclear Research, Dubna, Russia) to provide both samples with the same neutron fluency. We have processed the experimental data of irradiated Np-237 actinide samples and silicon detectors directly placed on two sections of the QUINTA setup without a lead shield-reflector. Applying the try and error method we have found found that the neutron energy for which the ratio of the fission cross section to the capture cross section of the actinide Np-237 from the nuclear data base is equal to the measured ratio of the fissioned and captured actinide isotopes. The retrieved distinct fission and capture cross sections for the distinct neutron energy from the nuclear data base describe the average values. The considered above experimental and earlier obtained data have been shown that the higher is the average neutron energy the smaller is the difference of the neutron fluency measurement between the two methods. This effect has been expected since the silicon detector method efficiently measures the fast neutrons of the energy higher than about 170 keV while the actinide method covers a wider energy range.

EXCITATION CURVES FOR THE REACTIONS Fe56(n, p)Mn56 AND Co59(n, α)Mn56

1964 ◽  
Vol 42 (6) ◽  
pp. 1030-1036 ◽  
Author(s):  
D. C. Santry ◽  
J. P. Butler
Keyword(s):  
Cross Section ◽  
Neutron Spectrum ◽  
Neutron Energy ◽  
Cross Sections ◽  
Effective Cross Section ◽  
Fission Neutron ◽  
Reaction Cross ◽  
Fission Neutron Spectrum ◽  
Threshold Energies ◽  
Reaction Cross Sections

Excitation curves for the reactions Fe56(n, p)Mn56 and Co59(n, α)Mn56 have been measured by the activation method from near threshold energies to 20.3 Mev. The measurements are relative to the known cross section for the S32(n, p)P32 reaction. Cross sections for both reactions increase smoothly with neutron energy and reach maximum values of 119 ± 4 mb for the Fe56(n, p) reaction at 13.6 Mev and 30.0 ± 0.9 mb for the Co59(n, α) reaction at 14.5 Mev. Above 15 Mev both cross sections decrease with neutron energy. From the excitation curves effective cross-section values for a fission-neutron spectrum have been calculated as 1.04 ± 0.05 mb for the (n, p) reaction and 0.140 ± 0.007 mb for the (n, α) reaction.

Cross Section Measurements for the 103Rh(n,n′)103Rhm Reaction from 0.122 to 14.74 MeV

1974 ◽  
Vol 52 (15) ◽  
pp. 1421-1428 ◽  
Author(s):  
D. C. Santry ◽  
J. P. Butler
Keyword(s):  
Neutron Flux ◽  
Cross Section ◽  
Neutron Spectrum ◽  
Cross Sections ◽  
Energy Levels ◽  
Effective Cross Section ◽  
Fission Neutron ◽  
Activation Method ◽  
Excitation Curve ◽  
Fission Neutron Spectrum

Cross sections for the production of 103Rhm were measured by the activation method. At energies below 5.3 MeV the neutron flux was measured with a calibrated neutron long counter, while at higher energies, measurements were made relative to the known cross section for the 32S(n,p)32P reaction. The shape of the Rh excitation curve is discussed in terms of known energy levels in 103Rh. An effective cross section for a 235U fission neutron spectrum calculated from the measured excitation curve is 724 ± 43 mb.

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