Validation of heavy water cross section using AmBe neutron source

Physical quantities derived from integral experiments can usually be measured much more accurately than that from differential nuclear data. The accurate knowledge of integral parameters provide excellent grounds for testing and tuning differential data such as, for instance, cross sections. Measurement of neutron leakage spectra with 252Cf neutron source located at sphere center is often used for integral experiments. While this type of experiments provide information for cross section tuning, however, care must be taken to avoid misleading interpretation, namely, at high energies due to the very low portion of high energy neutrons in 252Cf spectrum. This issue can be alleviated by the use of point source with different spectra shape. For that purpose one suitable candidate seems to be the AmBe neutron source which has a relatively high average energy and peak character of emitted neutrons. Indeed, AmBe seems an interesting option because the calculated leakage neutron spectra are not very sensitive to the input shape of the neutron spectra. Thus the neutron leakage spectra calculated using tabulated of International Organization for Standardization spectra is nearly the same as stilbene measured AmBe spectra as an input.

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

EPJ Web of Conferences ◽

10.1051/epjconf/202023918005 ◽

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.

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Inelastic cross sections of relativistic protons on Lead

HNPS Proceedings ◽

10.12681/hnps.2555 ◽

2019 ◽

Vol 18 ◽

pp. 49

Author(s):

M. Zamani ◽

S. Stoulos ◽

M. Fragopoulou ◽

M. Manolopoulou ◽

N. A. Sosnin ◽

...

Keyword(s):

Cross Section ◽

Neutron Source ◽

Cross Sections ◽

High Energy Physics ◽

Analytical Calculation ◽

High Energy ◽

Inelastic Cross Section ◽

Spallation Neutron Source ◽

Fitting Procedure ◽

Energy Physics

The inelastic cross section of relativistic protons in Lead was determined indirectly by measuring the neutron distribution along a Lead spallation neutron source. The spallation neutron source was irradiated by 1, 1.5 and 2 GeV protons. The experimental results were taken using passive methods. A fitting procedure has been applied to the experimental data and the results have been compared with analytical calculation of the produced hadrons’ spatial distribution based on High Energy Physics concepts. Using the beam attenuation coefficient the inelastic cross section of protons in Pb was estimated.

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Investigation of 127I(n,2n)126I and 23Na(n,2n)22Na Reactions Using 252Cf Neutron Source

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4039774 ◽

2019 ◽

Vol 5 (3) ◽

Cited By ~ 1

Author(s):

Martin Schulc ◽

Michal Košťál ◽

Evžen Novák ◽

Jan Šimon ◽

Nicola Burianová

Keyword(s):

Neutron Source ◽

Cross Sections ◽

Nuclear Data ◽

Reaction Rates ◽

Fission Neutron ◽

High Energy ◽

High Energy Tail ◽

252Cf Neutron Source ◽

Data Libraries ◽

Nuclear Data Libraries

This work deals with 23Na(n,2n)22Na and 127I(n,2n)126I reactions in the 252Cf spontaneous fission neutron source. 252Cf neutron source with approximate emission of 6·× 108 n/s was employed for the irradiation of sodium iodide. The spectrum-averaged cross sections (SACS) were then inferred from experimentally determined reaction rates and compared with calculations in MCNP6 using various nuclear data libraries. The experimental reaction rates were derived from the net peak areas (NPAs) measured using the high purity germanium spectroscopy. The measured SACS for the 23Na(n,2n)22Na reaction in the 252Cf spectrum was determined as equal to (8.98±0.32)·× 10−6 b. The resulting SACS for the 127I(n,2n)126I reaction in the 252Cf spectrum was derived as (2.044±0.0072)·× 10−3 b. These experimental data can be used for nuclear data libraries validation and to specify high energy tail of the 252Cf neutron spectrum.

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Total cross sections of eγ → $$ eX\overline{X} $$ processes with X = μ, γ, e via multiloop methods

Journal of High Energy Physics ◽

10.1007/jhep01(2021)144 ◽

2021 ◽

Vol 2021 (1) ◽

Author(s):

Roman N. Lee ◽

Alexey A. Lyubyakin ◽

Vyacheslav A. Stotsky

Keyword(s):

Cross Section ◽

Cross Sections ◽

Elliptic Integral ◽

High Energy ◽

Calculation Methods ◽

Complete Elliptic Integral ◽

Total Cross Sections ◽

Multiloop Calculation ◽

The Cross ◽

Analytical Expressions

Abstract Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes e−γ →$$ {e}^{-}X\overline{X} $$ e − X X ¯ with X = μ, γ or e at arbitrary energies. For the first two processes our results are expressed via classical polylogarithms. The cross section of e−γ → e−e−e+ is represented as a one-fold integral of complete elliptic integral K and logarithms. Using our results, we calculate the threshold and high-energy asymptotics and compare them with available results.

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Saturation effects in SIDIS at very forward rapidities

Journal of High Energy Physics ◽

10.1007/jhep07(2021)196 ◽

2021 ◽

Vol 2021 (7) ◽

Author(s):

E. Iancu ◽

A. H. Mueller ◽

D. N. Triantafyllopoulos ◽

S. Y. Wei

Keyword(s):

Inelastic Scattering ◽

Cross Section ◽

Cross Sections ◽

Virtual Photon ◽

Large Fraction ◽

Quark Distribution ◽

High Energy ◽

Longitudinal Momentum ◽

Black Disk ◽

Gluon Saturation

Abstract Using the dipole picture for electron-nucleus deep inelastic scattering at small Bjorken x, we study the effects of gluon saturation in the nuclear target on the cross-section for SIDIS (single inclusive hadron, or jet, production). We argue that the sensitivity of this process to gluon saturation can be enhanced by tagging on a hadron (or jet) which carries a large fraction z ≃ 1 of the longitudinal momentum of the virtual photon. This opens the possibility to study gluon saturation in relatively hard processes, where the virtuality Q2 is (much) larger than the target saturation momentum $$ {Q}_s^2 $$ Q s 2 , but such that z(1 − z)Q2 ≲ $$ {Q}_s^2 $$ Q s 2 . Working in the limit z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we predict new phenomena which would signal saturation in the SIDIS cross-section. For sufficiently low transverse momenta k⊥ ≪ Qs of the produced particle, the dominant contribution comes from elastic scattering in the black disk limit, which exposes the unintegrated quark distribution in the virtual photon. For larger momenta k⊥ ≳ Qs, inelastic collisions take the leading role. They explore gluon saturation via multiple scattering, leading to a Gaussian distribution in k⊥ centred around Qs. When z(1 − z)Q2 ≪ Q2, this results in a Cronin peak in the nuclear modification factor (the RpA ratio) at moderate values of x. With decreasing x, this peak is washed out by the high-energy evolution and replaced by nuclear suppression (RpA< 1) up to large momenta k⊥ ≫ Qs. Still for z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we also compute SIDIS cross-sections integrated over k⊥. We find that both elastic and inelastic scattering are controlled by the black disk limit, so they yield similar contributions, of zeroth order in the QCD coupling.

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THE ABSORPTION OF HIGH-ENERGY RADIATION, A MONTE CARLO STUDY: II. SPHERICAL GEOMETRY

Canadian Journal of Physics ◽

10.1139/p63-066 ◽

1963 ◽

Vol 41 (4) ◽

pp. 651-663

Author(s):

N. R. Steenberg

Keyword(s):

Cross Section ◽

Spherical Geometry ◽

Monte Carlo Study ◽

Nuclear Data ◽

High Energy ◽

Rare Gas ◽

Nuclear Radius ◽

Rigid Spheres ◽

High Energy Radiation ◽

The Individual

The absorption of radiation in a spherical obstacle composed of rigid spheres has been studied. The result is the absorption cross section of such an obstacle as a function of the free cross section and the number A of the individual spheres and of packing density. It is found that the usual rare-gas formula represents the cross section adequately. The analysis is applied to nuclear data for the absorption of 25-Bev/c protons by nuclei. It is found that for a nuclear radius R = r0A1/3 + δ, where δ is the radius of the nucleon, r0 = 1.17 fermi, δ = 1.05 fermi, and an average nucleon transparency a2 = 0.30 is consistent with the data.

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Study of the 232Th(n,f) Cross section at NCSR ‘Demokritos’ using Micromegas Detectors

HNPS Proceedings ◽

10.12681/hnps.2994 ◽

2020 ◽

Vol 27 ◽

pp. 106

Author(s):

Sotirios Chasapoglou ◽

A. Tsantiri ◽

A. Kalamara ◽

M. Kokkoris ◽

V. Michalopoulou ◽

...

Keyword(s):

Cross Section ◽

Cross Sections ◽

Nuclear Reactions ◽

Detection Efficiency ◽

High Energy ◽

Tandem Accelerator ◽

Line Detector ◽

Accelerator Driven Systems ◽

The Masses

The accurate knowledge of neutron-induced fission cross sections in actinides, is of great importance when it comes to the design of fast nuclear reactors, as well as accelerator driven systems. Specifically for the 232Th(n,f) case, the existing experimental datasets are quite discrepant in both the low and high energy MeV regions, thus leading to poor evaluations, a fact that in turn implies the need for more accurate measurements.In the present work, the total cross section of the 232Th(n,f) reaction has been measured relative to the 235U(n,f) and 238U(n,f) ones, at incident energies of 7.2, 8.4, 9.9 MeV and 14.8, 16.5, 17.8 MeV utilizing the 2H(d,n) and 3H(d,n) reactions respectively, which generally yield quasi-monoenergetic neutron beams. The experiments were performed at the 5.5 MV Tandem accelerator laboratory of N.C.S.R. “Demokritos”, using a Micromegas detector assembly and an ultra thin ThO2 target, especially prepared for fission measurements at n_ToF, CERN during its first phase of operations, using the painting technique. The masses of all actinide samples were determined via α-spectroscopy. The produced fission yields along with the results obtained from activation foils were studied in parallel, using both the NeusDesc [1] and MCNP5 [2] codes, taking into consideration competing nuclear reactions (e.g. deuteron break up), along with neutron elastic and inelastic scattering with the beam line, detector housing and experimental hall materials. Since the 232Th(n,f) reaction has a relatively low energy threshold and can thus be affected by parasitic neutrons originating from a variety of sources, the thorough characterization of the neutron flux impinging on the targets is a prerequisite for accurate cross-section measurements, especially in the absence of time-of-flight capabilities. Additional Monte-Carlo simulations were also performed coupling both GEF [3] and FLUKA [4] codes for the determination of the detection efficiency.

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Measurements of Displacement Cross Section of Tungsten under 389-MeV Proton Irradiation and Thermal Damage Recovery

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1024.95 ◽

2021 ◽

Vol 1024 ◽

pp. 95-101

Author(s):

Yosuke Iwamoto ◽

Makoto Yoshida ◽

Hiroki Matsuda ◽

Shin Ichiro Meigo ◽

Daiki Satoh ◽

...

Keyword(s):

Cross Section ◽

Cross Sections ◽

Thermal Conduction ◽

Thermal Damage ◽

Proton Irradiation ◽

High Energy ◽

Wire Sample ◽

Energy Proton ◽

Measured Displacement ◽

Mev Protons

For validating the number of displacements per atom (dpa) for tungsten under high-energy proton irradiation, we measured displacement cross sections related to defect-induced electrical resistivity changes in a tungsten wire sample under irradiation with 389-MeV protons under 10 K. The Gifford–McMahon cryocooler was used to cool the sample using a conductive coolant via thermal conduction plates of oxygen-free high-conductivity copper and electrical insulation sheets of aluminum nitride ceramic. In this experiment, the displacement cross section was 1612 ± 371 b for tungsten at 389 MeV. A comparison of the experimental displacement cross sections of tungsten with the calculated results obtained using Norgett–Robinson–Torrens (NRT) dpa and athermal recombination-corrected (arc) dpa cross sections indicates that arc-dpa was in better agreement with the experimental data than NRT-dpa; this is similar to the displacement cross sections of copper. From the measurements of damage recovery of the accumulated defects in tungsten through isochronal annealing, which is related to the defect concentration of the sample, approximately 20% of the damage was recovered at 60 K. This trend was similar to those observed in other experimental results for reactor neutrons.

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Note on the production of positron-electron pairs during the passage of β-particles through matter

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100020387 ◽

1938 ◽

Vol 34 (3) ◽

pp. 435-441 ◽

Cited By ~ 8

Author(s):

N. Feather ◽

J. V. Dunworth

Keyword(s):

Cross Section ◽

Atomic Number ◽

Cross Sections ◽

High Energy ◽

Coincidence Counting ◽

Electron Pairs ◽

Radioactive Substances

The method of coincidence counting has been applied to an investigation of the possible production of positron-electron pairs by the high energy β-particles from a source of uranium X in absorbers of aluminium, brass and lead. The results are not inconsistent with the high values recently reported for atomic cross-sections for the effect, nor with the suggestion that the atomic cross-section is proportional to the first power of the atomic number rather than the second. Suggestions are made for the use of the β-particles from artificially radioactive substances in an attempt to increase the sensitivity of the method.

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CESAR5.3: Isotopic depletion for Research and Testing Reactor decommissioning

EPJ Nuclear Sciences & Technologies ◽

10.1051/epjn/2018008 ◽

2018 ◽

Vol 4 ◽

pp. 10 ◽

Cited By ~ 1

Author(s):

Guillaume Ritter ◽

Romain Eschbach ◽

Richard Girieud ◽

Maxime Soulard

Keyword(s):

Nuclear Fuel ◽

Cross Section ◽

Cross Sections ◽

Power Plants ◽

Fuel Cycle ◽

Nuclear Data ◽

Computer Code ◽

Test Case ◽

Industrial Facilities ◽

Transport Code

CESAR stands in French for “simplified depletion applied to reprocessing”. The current version is now number 5.3 as it started 30 years ago from a long lasting cooperation with ORANO, co-owner of the code with CEA. This computer code can characterize several types of nuclear fuel assemblies, from the most regular PWR power plants to the most unexpected gas cooled and graphite moderated old timer research facility. Each type of fuel can also include numerous ranges of compositions like UOX, MOX, LEU or HEU. Such versatility comes from a broad catalog of cross section libraries, each corresponding to a specific reactor and fuel matrix design. CESAR goes beyond fuel characterization and can also provide an evaluation of structural materials activation. The cross-sections libraries are generated using the most refined assembly or core level transport code calculation schemes (CEA APOLLO2 or ERANOS), based on the European JEFF3.1.1 nuclear data base. Each new CESAR self shielded cross section library benefits all most recent CEA recommendations as for deterministic physics options. Resulting cross sections are organized as a function of burn up and initial fuel enrichment which allows to condensate this costly process into a series of Legendre polynomials. The final outcome is a fast, accurate and compact CESAR cross section library. Each library is fully validated, against a stochastic transport code (CEA TRIPOLI 4) if needed and against a reference depletion code (CEA DARWIN). Using CESAR does not require any of the neutron physics expertise implemented into cross section libraries generation. It is based on top quality nuclear data (JEFF3.1.1 for ∼400 isotopes) and includes up to date Bateman equation solving algorithms. However, defining a CESAR computation case can be very straightforward. Most results are only 3 steps away from any beginner's ambition: Initial composition, in core depletion and pool decay scenario. On top of a simple utilization architecture, CESAR includes a portable Graphical User Interface which can be broadly deployed in R&D or industrial facilities. Aging facilities currently face decommissioning and dismantling issues. This way to the end of the nuclear fuel cycle requires a careful assessment of source terms in the fuel, core structures and all parts of a facility that must be disposed of with “industrial nuclear” constraints. In that perspective, several CESAR cross section libraries were constructed for early CEA Research and Testing Reactors (RTR’s). The aim of this paper is to describe how CESAR operates and how it can be used to help these facilities care for waste disposal, nuclear materials transport or basic safety cases. The test case will be based on the PHEBUS Facility located at CEA − Cadarache.

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