Neutron-Production Double-Differential Cross Sections Research Articles

Neutron-production double-differential cross sections of natPb and 209Bi in proton-induced reactions near 100 MeV

The lack of double-differential cross-section (DDX) data for neutron production below the incident proton energy of 200 MeV hinders the validation of spallation models in technical applications, such as research and development of accelerator-driven systems (ADSs). The present study aims to obtain experimental DDX data for ADS spallation target materials in this energy region and identify issues related to the spallation models by comparing them with the analytical predictions. The DDXs for the (p,xn) reactions of natPb and 209Bi in the 100-MeV region were measured over an angular range of 30° to 150° using the time-of-flight method. The measurements were conducted at Kyoto University utilizing the FFAG accelerator. The DDXs obtained were compared with calculation results from Monte Carlo-based spallation models (INCL4.6/GEM, Bertini/GEM, JQMD/GEM, ISOBAR/GEM, CEM03.03, INCL4/ABLA, Bertini/ABLA, ISABEL/ABLA, INCL++/ABLA07, INCL++/GEMINI++, and INCL++/SMM) and the evaluated nuclear data library, JENDL-5. Comparison between the measured DDX and analytical values based on the spallation models and evaluated nuclear data library indicated that, in general, the CEM03.03 model demonstrated the closest match to the experimental values. Additionally, the comparison highlighted several issues that need to be addressed in order to improve the reproducibility of the proton-induced neutron-production DDX in the 100 MeV region by these spallation models and evaluated nuclear data library. To enhance the reproducibility of underperforming spallation models and evaluated nuclear data library, it is recommended to address each of the issues identified in this study.

Estimation of uncertainty in lead spallation particle multiplicity and its propagation to a neutron energy spectrum

ABSTRACT This paper presents an approach to uncertainty estimation of spallation particle multiplicity of lead (natPb), primarily focusing on proton-induced spallation neutron multiplicity (xpn ) and its propagation to a neutron energy spectrum. The xpn uncertainty is estimated from experimental proton-induced neutron-production double-differential cross-sections (DDXs) and model calculations with the Particle and Heavy Ion Transport code System (PHITS). Uncertainties in multiplicities for (n, xn), (p, xp), and (n, xp) reactions are then inferred from the estimated x pn uncertainty and the PHITS calculation. Using these uncertainties, uncertainty in a neutron energy spectrum produced from a thick natPb target bombarded with 500 MeV proton beams, measured in a previous experiment, is quantified by a random sampling technique, and propagation to the neutron energy spectrum is examined. Relatively large uncertainty intervals (UIs) are observed outside the lower limit of the measurement range, which is prominent in the backward directions. Our findings suggest that a reliable assessment of spallation neutron energy spectra requires systematic DDX experiments for detector angles and incident energies below 100 MeV as well as neutron energy spectrum measurements at lower energies below ∼1.4 MeV with an accuracy below the quantified UIs.

Measurement of neutron-production double-differential cross sections of [formula omitted]C, 27Al, [formula omitted]Fe, and [formula omitted]Pb by 20, 34, 48, 63, and 78 MeV protons in the most-forward direction

In this study, the neutron-production double-differential cross sections (DDXs) of natC, 27Al, natFe, and natPb bombarded by 20, 34, 48, 63, and 78 MeV protons were measured in the most-forward direction by the time-of-flight (TOF) method using a liquid organic scintillator. Characteristic peak structures were observed in the measured neutron spectra, especially for light nuclei. The experimental data were compared with the results from the Monte Carlo simulation code “Particle and Heavy Ion Transport code System” (PHITS) using the theoretical model Liège Intranuclear Cascade (INCL) or using the Japanese evaluated nuclear data library (JENDL-4.0/HE). While the results of JENDL-4.0/HE were in agreement with the experimental data better than those of INCL, neither could reproduce the measured peak structures for some combinations of the beam and target. For the energy-integrated cross sections, JENDL-4.0/HE reproduced the experimental data within a factor of two in all cases. On the other hand, INCL gave values up to approximately six times larger than the experimental ones.

Validation of PHITS Spallation Models from the Perspective of the Shielding Design of Transmutation Experimental Facility

The impact of different spallation models implemented in the particle transport code PHITS on the shielding design of Transmutation Experimental Facility is investigated. For 400-MeV proton incident on a lead-bismuth eutectic target, an effective dose rate at the end of a thick radiation shield (3-m-thick iron and 3-m-thick concrete) calculated by the Liege intranuclear cascade (INC) model version 4.6 (INCL4.6) coupled with the GEMcode (INCL4.6/GEM) yields about twice as high as the Bertini INC model (Bertini/GEM). A comparison with experimental data for 500-MeV proton incident on a thick lead target suggest that the prediction accuracy of INCL4.6/GEM would be better than that of Bertini/GEM. In contrast, it is found that the dose rates in beam ducts in front of targets calculated by the INCL4.6/GEMare lower than those by the Bertini/GEM. Since both models underestimate the experimental results for neutron-production doubledifferential cross sections at 180◦ for 140-MeV proton incident on carbon, iron, and gold targets, it is concluded that it is necessary to allow a margin for uncertainty caused by the spallation models, which is a factor of two, in estimating the dose rate induced by neutron streaming through a beam duct.

Measurement of Neutron Production Double-differential Cross-sections on Carbon Bombarded with 430 MeV/Nucleon Carbon Ions

Measurement of Neutron Production Double-differential Cross-sections on Carbon Bombarded with 430 MeV/Nucleon Carbon Ions

Neutron time-of-flight spectrometer based on HIRFL for studies of spallation reactions related to ADS project

A Neutron Time-of-Flight(NTOF) spectrometer, based at the Heavy Ion Research Facility in Lanzhou(HIRFL) was developed for studies of neutron production of proton induced spallation reactions related to the ADS project. After the presentation of comparisons between calculated spallation neutron production doubledifferential cross sections and the available experimental data, a detailed description of the NTOF spectrometer is given. Test beam results show that the spectrometer works well and data analysis procedures are established.The comparisons of the test beam neutron spectra with those of GEANT4 simulations are presented.

Measurements and Monte Carlo calculations of forward-angle secondary-neutron-production cross-sections for 137 and 200 MeV proton-induced reactions in carbon

Secondary neutron-production double-differential cross-sections (DDXs) have been measured from interactions of 137MeV and 200MeV protons in a natural carbon target. The data were measured between 0° and 25° in the laboratory. DDXs were obtained with high energy resolution in the energy region from 3MeV up to the maximum energy. The experimental data of 137MeV protons at 10° and 25° were in good agreement with that of 113MeV protons at 7.5° and 30° at LANSCE/WNR in the energy region below 80MeV. Benchmark calculations were carried out with the PHITS code using the evaluated nuclear data files of JENDL/HE-2007 and ENDF/B-VII, and the theoretical models of Bertini-GEM and ISOBAR-GEM. For the 137MeV proton incidence, calculations using JENDL/HE-2007 generally reproduced the shape and the intensity of experimental spectra well including the ground state of the 12N state produced by the 12C(p,n)12N reaction. For the 200MeV proton incidence, all calculated results underestimated the experimental data by the factor of two except for the calculated result using ISOBAR model. ISOBAR predicts the nucleon emission to the forward angles qualitatively better than the Bertini model. These experimental data will be useful to evaluate the carbon data and as benchmark data for investigating the validity of the Monte Carlo simulation for the shielding design of accelerator facilities.

Neutron-Production Double-Differential Cross Sections from Heavy-Ion Interactions

Neutron-Production Double-Differential Cross Sections from Heavy-Ion Interactions

Measurements of Neutron-Induced Neutron-Production Double-Differential Cross Sections from 50 to 150 MeV

Measurements of Neutron-Induced Neutron-Production Double-Differential Cross Sections from 50 to 150 MeV

Measurement of neutron-production double-differential cross-sections on carbon bombarded with 290-MeV/nucleon carbon and oxygen ions

Neutron-production double-differential cross-sections on carbon–carbon and oxygen–carbon reactions with incident heavy-ion energy of 290MeV/nucleon were measured by time-of-flight method using liquid organic scintillators. By use of a detection system specialized for low-energy neutrons, the cross-sections were obtained in a wide energy region from several hundred MeV down to 0.6MeV for the oxygen-ion incidences. The experimental data were compared with the calculation results using the Monte-Carlo simulation code, PHITS. The PHITS results gave an overall agreement with the measured data within a factor of two.

Measurements of Neutron-production Double-differential Cross-sections at 100 MeV Neutron-Incidence on Fe

Measurements of Neutron-production Double-differential Cross-sections at 100 MeV Neutron-Incidence on Fe

Neutron-Production Double-Differential Cross Sections for 100 MeV Neutron-Incidence on In

Neutron-production double-differential cross sections were measured on Indium (In) for neutron-induced reactions of 90 – 110 MeV at the WNR facility of Los Alamos Neutron Science Center. Incident particles were neutrons produced by an 800 MeV proton-bombarded spallation target. Six NE213 liquid organic scintillators were used as neutron detectors. The results are parameterized by the moving source model and compared with calculated data.

Feに対する高エネルギー(n,xn)二重微分断面積測定

Feに対する高エネルギー(n,xn)二重微分断面積測定

Probing the density dependence of the quantum molecular dynamics potential with spallation neutrons induced by 1.2 GeV protons on Al, Fe, Zr, and Pb

The dependence of spallation neutron production double-differential cross sections on the density of the quantum molecular dynamics potential is investigated in $p$+Al, Fe, Zr, and Pb reactions at 1.2 GeV. It is shown that the cascade component of the neutron spectra is largely unaffected by the parameters of the density-dependent potential. As for the evaporative part ($<20$ MeV), some differences are marked only for Pb. Calculated results with a Skyrme-type equation of state of $K=300$ MeV reproduce the neutron spectra for the reactions under study.

Measurement of pion induced neutron-production double-differential cross sections onFeandPbat870MeVand2.1GeV

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Measurement of 0.8 and 1.5 GeV Proton Induced Neutron Production Cross Sections at 0°

Neutron-production double-differential cross sections at 0° were measured for proton-induced reactions on Fe and Pb targets at 0.8 and 1.5 GeV. The experiment was performed at the π2 beam line of the 12 GeV proton synchrotron in High Energy Accelerator Research Organization (KEK). Neutrons were measured by time-of-flight technique with two different flight path lengths, i.e. 3.5 and 5.0 m at 0.8 and 1.5 GeV, respectively. NE213 liquid organic scintillators 12.7 cm in diameter and 12.7 cm in thickness were set at 0° as neutron detector. For the improvement of the energy resolution, the scintillator was connected with three Hamamatsu H2431 photomultipliers 5.1 cm in diameter. The neutron detection efficiencies were obtained by the SCINFUL-QMD code. The experimental data were compared with the calculation results of the intranuclear-cascade-evaporation (INC/E) and the quantum-molecular-dynamics (QMD) models.

Neutron-Production Double-Differential Cross Sections of Iron and Lead by 0.8 and 1.5 GeV Protons in the Most-Forward Direction

Neutron-production double-differential cross sections of iron and lead for 0.8 and 1.5 GeV protons incidences were measured in the most-forward direction. Neutrons were measured by the time-of-flight (TOF) method. An NE213 liquid organic scintillator was set at 0° as a neutron detector. Neutron detection efficiencies were obtained by calculations with a Monte Carlo simulation code SCINFUL-QMD. The present experimental data were compared with other reported experimental data and the results of calculation codes based on Intranuclear-Cascade-Evaporation (INC/E) and Quantum Molecular Dynamics (QMD) models. For neutrons associated with Δ formation, the present data deviated from predictions of these codes, and gave magnitudes between them in both 0.8 and 1.5 GeV incidences.

Neutron-Production Double-Differential Cross Sections of Iron and Lead by 0.8 and 1.5 GeV Protons in the Most-Forward Direction

Neutron-Production Double-Differential Cross Sections of Iron and Lead by 0.8 and 1.5 GeV Protons in the Most-Forward Direction

Measurement of Neutron-Production Double-Differential Cross Sections for 0.8 and 1.5 GeV Proton Incidence in the Most-Forward Directions

Neutron-production double-differential cross sections in the most-forward directions were measured for proton-induced reactions on Fe and Pb targets at 0.8 and 1.5 GeV. The experiment was performed at the π2 beam line of the 12 GeV proton synchrotron in High Energy Accelerator Research Organization (KEK). Neutrons were measured by time-of-flight technique with two different flight path lengths, i.e. 3.5 and 5.0 m at 0.8 and 1.5 GeV, respectively. NE213 liquid organic scintillators 12.7 cm in diameter and 12.7 cm in thickness were set at 0° and 5° as neutron detectors. For the improvement of the energy resolution, the scintillator at 0° was connected with three Hamamatsu H2431 photomultipliers 5.1 cm in diameter. The neutron detection efficiencies were obtained by the SCINFUL-QMD code. The experimental data were compared with the calculation results of the intranuclear-cascade-evaporation and QMD models.

Measurement of Neutron-Production Double-Differential Cross Sections for Intermediate Energy Pion Incident Reaction

Neutron-production double-differential cross sections for 870-MeV π+ and π− and 2.1-GeV π+ mesons incident on iron and lead targets were measured with NE213 liquid scintillators by time-of-flight technique. NE213 liquid scintillators 12.7 cm in diameter and 12.7 cm thick were placed in directions of 15, 30, 60, 90, 120 and 150°. The typical flight path length was 1.5 m. Neutron detection efficiencies were derived from the calculation results of SCINFUL and CECIL codes. The experimental results were compared with the JAM code. The double differential cross sections calculated by the JAM code disagree with experimental data at neutron energies below about 30 MeV. JAM overestimates π+-incident neutron-production cross sections in forward angles at neutron energies of 100 to 500 MeV.