Intranuclear Cascade Model Research Articles

$\eta$ η and $\omega$ ω mesons as new degrees of freedom in the intranuclear cascade model INCL

The intranuclear cascade model INCL (Liege Intranuclear Cascade) is now able to simulate spallation reactions induced by projectiles with energies up to roughly 15 GeV. This was made possible thanks to the implementation of multipion emission in the NN, $\Delta$ N and $\pi$ N interactions. The results obtained with reactions on nuclei induced by nucleons or pions gave confidence in the model. A next step will be the addition of the strange particles, $\Lambda$ , $\Sigma$ and kaons, in order to not only refine the high-energy modeling, but also to extend the capabilities of INCL, as studying hypernucleus physics. Between those two versions of the code, the possibility to treat the $\eta$ and $\omega$ mesons in INCL has been performed and this is the topic of this paper. Production yields of these mesons increase with energy and it is interesting to test their roles at higher energies. More specifically, studies of $\eta$ rare decays benefit from accurate simulations of its production. These are the two reasons for their implementation. Ingredients of the model, like elementary reaction cross sections, are discussed and comparisons with experimental data are carried out to test the reliability of those particle productions.

HEIR: A High-Energy Intra-Nuclear Cascade Liège-based Residual nuclear data library for simulation with FISPACT-II

FISPACT-II is an advanced activation/transmutation and inventory code that employs the most up-to-date and sophisticated nuclear data forms, including the full TENDL-2017 library. TENDL includes residual nuclide production for incident particle energies up to 200 MeV. To address the needs of activation–transmutation simulation in incident-particle fields with energies up to and above 1 GeV, FISPACT-II has been extended to splice TENDL standard ENDF-6 nuclear data with extended nuclear data forms. Comparisons between JENDL-2007/HE, HEAD-2009, and the most recent intra-nuclear cascade models found within Geant4 led to an updated method for residual nuclide nuclear data production. This has been achieved with an automated INCL++/ABLA process that produces complete residual cross section format (MF=10) for activation/transmutation and inventory calculations. The current High-Energy Intra-Nuclear Cascade Liège-based Residual (HEIR-0.1) library includes proton-induced cross sections up to 1 GeV for 2095 targets. These data are available with the most recent release 4.0 of FISPACT-II.

Nuclide production in spallation reactions: How useful are the simulations?

INCL (Liège IntraNuclear Cascade model) combined with a deexcitation code has been used a lot for numerous simulations of spallation reactions during the last two decades. We go back over some of those simulations to address the capabilities of such codes and to show some improvements. The four examples of simultation are: the EURISOL project, the MEGAPIE target, the ESS facility, and the cosmogenic nuclide production. The goal is to discuss respectively designing and optimisation, predictive power and reliability, feasibility and uncertainty estimate, and the use of modeling to mitigate lack of experimental data.

High-Energy Activation Simulation Coupling TENDL and SPACS with FISPACT-II

To address the needs of activation-transmutation simulation in incident-particle fields with energies above a few hundred MeV, the FISPACT-II code has been extended to splice TENDL standard ENDF-6 nuclear data with extended nuclear data forms. The JENDL-2007/HE and HEAD-2009 libraries were processed for FISPACT-II and used to demonstrate the capabilities of the new code version. Tests of the libraries and comparisons against both experimental yield data and the most recent intra-nuclear cascade model results demonstrate that there is need for improved nuclear data libraries up to and above 1 GeV. Simulations on lead targets show that important radionuclides, such as 148Gd, can vary by more than an order of magnitude where more advanced models find agreement within the experimental uncertainties.

Angular distribution measurement for 12C fragmentation via 12C + 12C scattering at 100 MeV/u**Supported by National Natural Science Foundation of China (11705123, 11475013, 11035007, 11175011), China Postdoctoral Science Foundation (2016M591911) and Natural Science Foundation of Jiangsu Province (BK20160306)

The angular distributions and energy spectra of 11B, 10B, and 9Be fragments of 12C in the angular range from 1.0° to 7.5° at 100 MeV/u were obtained via 12C + 12C scattering. Detailed comparisons are presented between the experimental data and the modified antisymmetrized molecular dynamics (AMD-FM), binary intranuclear cascade model (BIC) and Liège intranuclear cascade model (INCL++). The experimental angular distributions and energy spectra are well reproduced by the AMD-FM calculations but fail to be reproduced by the physical models installed in the Geant4 program, including the BIC and INCL++ models.

Measurement of activation cross sections of the target and the proton beam window materials at J-PARC

To improve the accuracy of the nuclear design for spallation neutron sources and transmutation systems, nuclear reaction cross sections are required. Considering decommissioning of the accelerator facilities, accurate cross sections are mandatory. The activation cross sections have been measured in several facilities. However, they have low accuracy and precision. Especially, since there is almost no data for 3 GeV protons which are used for the spallation neutron source (MLF) in J-PARC, the experimental data is required for in order to improve the target materials. For the sake of the forthcoming full-time measurement of the activation cross sections for various nuclei, we measured the cross sections of aluminium with 0.4 GeV, 1.3 GeV, 2.2 GeV, and 3.0 GeV protons as a test case. It was found that more accurate data than current ones would be measured by using precise beam controls and highly accurate beam monitoring. We compared the experimental data, the evaluated data (JENDLHE/2007), and the calculations with several intranuclear cascade models using the PHITS code. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated by about 40%. This arises from the evaporation model (GEM) being included in PHITS code. We found that the calculations could be made to agree with the experimental data by upgrading the PHITS code.

Excitation of baryon resonances in charge-exchange reactions of heavy nuclei

The Liège intranuclear-cascade model (INCL) has been improved using a refined description of the matter and energy densities in the nuclear surface. Hartree-Fock-Bogoliubov calculations with the Skyrme interaction were used to obtain a more realistic description of the proton and neutron density profiles. We find that the new approach, together with a realistic modeling of the de-excitation process of the nuclear pre-fragments, improves the description of the production cross sections of the heaviest nuclear residues produced by charge-exchange processes in spallation reactions, where the excitation of baryonic resonances plays an important role.

Proton-induced activation cross section measurement for aluminum with proton energy range from 0.4 to 3 GeV at J-PARC

ABSTRACT We have started an experimental program to measure activation cross sections systematically in the proton-induced spallation reaction in structural materials commonly used in high-intensity proton accelerator-based facilities, such as Japan Proton Accelerator Research Complex (J-PARC). As the first step of the program, aluminum (Al) was chosen to verify the adequacy of the measurement technique implemented in a J-PARC proton beam environment because data of Al have been relatively well studied both by experimental measurement and simulation. Activation cross sections of 7Be, 22Na, and 24Na in Al were measured at proton energy points from 0.4, 1.3, 2.2 to 3.0 GeV, which could be delivered smoothly from the synchrotron. The validity of experimental data has been verified by introducing an effective proton numbers determination procedure. We compared the measured data with existing experimental data, the evaluated data (JENDL-HE/2007), and the calculations with several intra-nuclear cascade models by the Particle and Heavy Ion Transport code System (PHITS) code. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated about 40%. This could come from the evaporation model (generalized evaporation model) being implemented in the PHITS code. We found that the calculations agreed with the experimental data by an upgraded PHITS code.

Estimating model bias over the complete nuclide chart with sparse Gaussian processes at the example of INCL/ABLA and double-differential neutron spectra

Predictions of nuclear models guide the design of nuclear facilities to ensure their safe and efficient operation. Because nuclear models often do not perfectly reproduce available experimental data, decisions based on their predictions may not be optimal. Awareness about systematic deviations between models and experimental data helps to alleviate this problem. This paper shows how a sparse approximation to Gaussian processes can be used to estimate the model bias over the complete nuclide chart at the example of inclusive double-differential neutron spectra for incident protons above 100 MeV. A powerful feature of the presented approach is the ability to predict the model bias for energies, angles, and isotopes where data are missing. The number of experimental data points that can be taken into account is at least in the order of magnitude of 104 thanks to the sparse approximation. The approach is applied to the Liège intranuclear cascade model coupled to the evaporation code ABLA. The results suggest that sparse Gaussian process regression is a viable candidate to perform global and quantitative assessments of models. Limitations of a philosophical nature of this (and any other) approach are also discussed.

Non-equilibrium processes in p + Ag collisions at GeV energies

The double differential spectra ${d}^{2}\ensuremath{\sigma}/d\mathrm{\ensuremath{\Omega}}dE$ of $p$, $d$, $t$, $^{3,4,6}\mathrm{He}$, $^{6,7,8,9}\mathrm{Li}$, $^{7,9,10}\mathrm{Be}$, and $^{10,11,12}\mathrm{B}$ were measured at seven scattering angles, ${15.6}^{\ensuremath{\circ}}$, ${20}^{\ensuremath{\circ}}$, ${35}^{\ensuremath{\circ}}$, ${50}^{\ensuremath{\circ}}$, ${65}^{\ensuremath{\circ}}$, ${80}^{\ensuremath{\circ}}$, and ${100}^{\ensuremath{\circ}}$, in the laboratory system for proton induced reactions on a silver target. Measurements were done for three proton energies: 1.2, 1.9, and 2.5 GeV. The experimental data were compared to calculations performed by means of two-step theoretical microscopic models. The first step of the reaction was described by the intranuclear cascade model incl4.6 and the second one by four different models (ABLA07, GEM2, gemini++, and SMM) using their standard parameter settings. Systematic deviations of the data from predictions of the models were observed. The deviations were especially large for the forward scattering angles and for the kinetic energy of emitted particles in the range from about 50 to 150 MeV. This suggests that some important non-equilibrium mechanism is lacking in the present day microscopic models of proton-nucleus collisions in the studied beam energy range.

Spallation reaction study for the long-lived fission products in nuclear waste: Cross section measurements for 137Cs, 90Sr and 107Pd using inverse kinematics method

Spallation reaction study has been performed for the long-lived fission products 137Cs, 90Sr and 107Pd. Isotopic cross sections on proton and deuteron were obtained by using the inverse kinematics technique at the RIKEN Radioactive Isotope Beam Factory. It was found that the deuteron-induced cross sections are larger than the proton-induced ones for the light-mass products. The experimental data were compared with the SPACS semi-empirical parameterization and a theoretical calculation including both the intra-nuclear cascade and evaporation models by the PHITS transport code. It was found that the spallation reaction could be a promising mechanism for the transmutation of 137Cs and 90Sr due to the large total cross section.

Nuclear medium effects in muonic neutrino interactions with energies from 0.2 to 1.5 GeV

Nuclear reactions induced by muon neutrino with energies in the range from 0.2 to 1.5 GeV in Monte Carlo calculations framework in the intra-nuclear cascade model are studied. This study was done by comparison between the available experimental data and theoretical values of total cross section, and the energy distribution of emitted lepton energy in the reaction muon neutrino-nucleus, using the targets: $^{12}$C, $^{16}$O, $^{27}$Al, $^{40}$Ar, $^{56}$Fe and $^{208}$Pb. A phenomenological toy model of primary neutrino-nucleon interaction gives a good agreement of our theoretical inclusive neutrino nucleus cross in comparison with the available experimental data. Some interesting results on the behavior of the cross section as function of 1p-1n and higher contributions are also sketched. The previous results on the percentage of fake events related in available experiments in $^{12}$C were expanded for the set studied nuclei. With the increase of mass target, the nuclear effects in the cross sections were observed along with the importance to take into account fake events in the reactions.

Improvement of one-nucleon removal and total reaction cross sections in the Liège intranuclear-cascade model using Hartree-Fock-Bogoliubov calculations

The prediction of one-nucleon-removal cross sections by the Liege intranuclear-cascade model has been improved using a refined description of the matter and energy densities in the nuclear surface. Hartree-Fock-Bogoliubov calculations with the Skyrme interaction are used to obtain a more realistic description of the radial-density distributions of protons and neutrons, as well as the excitation-energy uncorrelation at the nuclear surface due to quantum effects and short-range correlations. The results are compared with experimental data covering a large range of nuclei, from carbon to uranium, and projectile kinetic energies. We find that the new approach is in good agreement with experimental data of one-nucleon-removal cross sections covering a broad range in nuclei and energies. The new ingredients also improve the description of total reaction cross sections induced by protons at low energies, the production cross sections of heaviest residues close to the projectile, and the triple-differential cross sections for one-proton removal. However, other observables such as quadruple-differential cross sections of coincident protons do not present any sizable sensitivity to the new approach. Finally, the model is also tested for light-ion-induced reactions. It is shown that the new parameters can give a reasonable description of the nucleus-nucleus total reaction cross sections at high energies.

Measurements and analysis of [formula omitted]Hf production cross sections under [formula omitted]Ta and [formula omitted]W irradiation by protons with 0.04–2.6 GeV energies

This paper presents the results of experimental determination and computational simulation of the independent cross sections of 178m2Hf production in natTa and natW thin targets irradiated by mono-energetic proton beams in the energy range from ∼0.04 up to 2.6 GeV. The cross sections were determined using the γ-spectrometry technique without chemical separation of irradiated samples. The obtained experimental results were compared with the results of simulations based on the modified CEM03.03-ext intranuclear cascade model, which allows to analyze both the cross sections of residual nuclei production and the probabilities of long-lived isomeric states formation. Verification of the isomeric yield calculation model was demonstrated based on experimental data on high-spin isomer production cross sections in 208Pb target irradiated by protons.

An intranuclear cascade model for inelastic scattering and breakup reactions involving deuterons and alpha particles

ABSTRACT The intranuclear cascade model is extended to cluster-induced (deuteron and alpha particle) nuclear reactions involving inelastic scattering and breakup reactions. The proposed model explains the projectile breakup process by describing the projectile cluster as a superposition of several states. The incident cluster and the produced cluster are assumed to be collections of independent particles and may undergo nuclear interaction through nucleon–nucleon interaction with the target nucleus. Trajectory deflections for the projectile and ejecta are incorporated in the model to account for angular distributions. Calculations with the proposed model followed by the generalized evaporation model are performed for validation by comparing with experimental double-differential cross-section spectra produced by bombarding an 27Al target separately with 80-MeV and 99.6-MeV deuterons and 140-MeV alpha particles. The calculation results show good agreement with experimental spectra.

Spatial distribution of the atmospheric radionuclide production by galactic cosmic rays and its imprint in natural archives

We used the GEANT4 toolkit to simulate the altitude and latitude profiles of the production rate of 14C, 10Be and 36Cl radionuclides by the galactic cosmic ray (GCR) interactions in the terrestrial atmosphere at a varying geomagnetic field. We found that applying two intranuclear cascade models incorporated in GEANT4 (Binary Intranuclear Cascade, BIC, and Bertini Intranuclear Cascade, BERT) result in significantly different production rate values. We present the conclusions about the certain model relevance to the abundance of these isotopes in the surface fallout, ice-core records and lunar soil depth profile. Comparison of our simulations with the recent publication of Poluianov et al. (2016) shows a good agreement for 14C (BIC) and 10Be (BERT) and a definite by the factor 2–3 difference in the 36Cl (BIC) atmospheric yield functions. Also, the mean level and amplitude of the 10Be variations in polar ice from central regions of Antarctica and Greenland could be accounted for its tropospheric production by GCRs. The fallout rate of 36Cl there can be explained assuming its additional input from the stratosphere. Significant additional variations of radionuclide sedimentation rate in polar regions may arise due to tropopause height changes even at a constant atmospheric production rate of the certain isotope.

Theoretical analysis and evaluation for neutron-induced reaction on 239Pu

The nuclear data of n+239Pu reaction for the incident energy up to 200MeV are currently required for the study of new-generation nuclear systems. To meet this requirement, all cross sections, angular distributions, energy spectra, double differential cross sections of neutron, proton, deuteron, triton, helium-3 and alpha emissions and the number of neutron per fission for n+239Pu reaction are consistently calculated and analyzed by theoretical nuclear models in the energy range of En⩽200MeV. The theoretical models include the optical model, the distorted wave Born approximation theory, the Hauser-Feshbach theory, the fission model, the evaporation model, the exciton model and the intranuclear cascade model. The calculated results are compared with recent experimental data and the evaluated data from ENDF/B-VII and JENDL-4.

Isotopic production cross sections of residual nuclei in the spallation reactionXe136(200AMeV)+p

The residual nuclei produced in the spallation reaction of Xe-136 nuclei at 200A MeV on protons have been studied by measuring the isotopic distributions for the elements from cadmium (Z = 48) to cesium (Z = 55) by using the fragment separator (FRS) spectrometer at GSI and the inverse kinematics technique. This is one of the few measurements performed at such a low projectile energy, close to the validity limit for intranuclear cascade models such as INCL or ISABEL. The experimental results have been compared to these intranuclear cascade codes coupled to the evaporation code ABLA. Both code combinations reproduce qualitatively the measured isotopic distributions; however, both underestimate the production of residues with mass numbers between 126 and 134. The measured cross sections are of interest for the planning of future radioactive beam or neutron source facilities.

Calculation and Evaluation for the n+51V Reaction

A set of optical model potential parameters for the n+51V reaction is obtained based on the experimental data of the total cross section, elastic scattering cross section, and elastic scattering angular distribution at incident energies up to 300 MeV. All cross sections, angular distributions, energy spectra, and double-differential cross sections for the n+51V reaction are consistently calculated and analyzed at incident neutron energies below 250 MeV. The theoretical nuclear models including the optical model, distorted wave Born approximation theory, Hauser-Feshbach theory, evaporation model, exciton model, and intranuclear cascade model are used in the analysis. The calculated results are compared with the experimental data and the evaluated results in ENDF/B-VII.1 and JENDL-4.

Modulation of galactic cosmic rays and its traces in isotopic tracks on the Earth and the moon

The high-altitude track of the rates of production of cosmogenic isotopes 14С, 10Be and 36Cl in the Earth’s atmosphere under the action of galactic cosmic rays is calculated using different intranuclear cascade models in the GEANT4 environment. Inferences based on these models are discussed in comparison to the available experimental data on these isotopes.