The Liège Intranuclear Cascade model, INCL4, has been developed to describe spallation reactions, i.e. nucleon and light charged particle induced collisions in the 100 MeV – 3 GeV energy range. ...Extensive comparisons with experimental data covering all possible reaction channels have shown that, coupled to the ABLA07 de-excitation code from GSI, it is presently one of the most reliable models in its domain. Recently, the treatment of composite particle as projectlies has been revisited mainly to improve predictions related to secondary reactions in spallation targets. An example regarding astatine production in LBE targets will be shown. Also, the model has been extended to light ion (up to oxygen) induced reactions, mostly for medical and space application purposes. This version is available in GEANT4. The first results indicate that the model agrees at least as well as other models with experimental data. In this paper, the different assumptions and ingredients of the model will be presented and comparisons with relevant experimental data will be shown. The sensitivity to the de-excitation stage is also discussed.
The recent developments of the Liège intranuclear cascade model INCL are reviewed. The INCL4.6 version of this model was able when coupled with the ABLA07 de-excitation code, to describe rather well ...a huge set of experimental data in an incident energy range spanning between 200 MeV and 3 GeV, as it has been testified by an intercomparison of spallation codes organized by the IAEA. Since that time, the model has been implemented in several nuclear particle transport codes. Therefore, the possible applications of INCL have been enlarged to focus on diverse fields, and in the recent years, the model has been further developed to be applicable to these new issues and also to cope with remaining deficiencies. The new features include: i) a sophisticated dynamical model for light cluster emission (up to O ions), ii) the accommodation of light nuclei as projectiles, iii) a new procedure to take account of the fuzziness of the Fermi surface, and iv) an extension of the model to higher energy. The aim of this contribution is to present for the first time and to discuss the physics of the added features, and to give a hint about the performances of the new model.
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.
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The intranuclear cascade model INCL (Liège 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
,
Δ
N
and
π
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,
Λ
,
Σ
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
η
and
ω
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
η
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.
A model is proposed to describe emission of light charged clusters during the cascade stage in nucleon-induced spallation reactions. It consists in implementing a surface percolation procedure into ...the Liège intranuclear cascade (INCL4) model: when a nucleon is ready to leave the nuclear surface, it is allowed to drag along a cluster of nucleons, under some conditions of closeness in phase space. This possibility relies on the instantaneous dynamical phase space occupancy in the nuclear surface. The following clusters are considered:
d,t,
3
He,
4
He
. Good agreement is obtained with experimental data relative to heavy and medium-heavy targets at two different energies. It is shown that the implementation of light cluster emission in the cascade stage also improves our previous results for residue mass spectra.
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.
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This article focuses on spallation reactions,
i.e.
interactions of energetic nucleons, basically with a kinetic energy in the 100MeV to a few GeV range, with a target nucleus. These processes are ...described rather successfully by the so-called Intranuclear Cascade (INC) plus evaporation models. They can be viewed as a first stage of nucleon-nucleon collisions, ejecting fast particles, followed by evaporation of slow particles from the target remnant. These cascade + evaporation models have, now, globally reached a high level of predictive power, owing in particular to successive research programs. The present work, which is an outcome of one of these programs, the recent European Union ANDES research program, deals with a set of reactions (or observable quantities), which can be due to a single collision, such as the one-nucleon removal reactions or the quasi-elastic elastic process. A survey of the experimental data is presented, which allows to clearly point out that, often, the INC models are unsatisfactory for the description of these peculiar events, whereas they are rather successful for the rest of the experimental data. This paradoxical situation is tentatively related to quasi-particle effects which are neglected in INC models.
Astatine isotopes can be produced in liquid lead-bismuth eutectic targets through proton-induced double charge exchange reactions on bismuth or in secondary helium-induced interactions. Models ...implemented into the most common high-energy transport codes generally have difficulties to correctly estimate their production yields as was shown recently by the ISOLDE Collaboration, which measured release rates from a lead-bismuth target irradiated by 1.4 and 1 GeV protons. In this paper, we first study the capability of the new version of the Liège intranuclear cascade model, INCL4.6, coupled to the deexcitation code ABLA07 to predict the different elementary reactions involved in the production of such isotopes through a detailed comparison of the model with the available experimental data from the literature. Although a few remaining deficiencies are identified, very satisfactory results are found, thanks in particular to improvements brought recently on the treatment of low-energy helium-induced reactions. The implementation of the models into MCNPX allows identifying the respective contributions of the different possible reaction channels in the ISOLDE case. Finally, the full simulation of the ISOLDE experiment is performed, taking into account the likely rather long diffusion time from the target, and compared with the measured diffusion rates for the different astatine isotopes, at the two studied energies, 1.4 and 1 GeV. The shape of the isotopic distribution is perfectly reproduced as well as the absolute release rates, assuming in the calculation a diffusion time between 5 and 10hours. This work finally shows that our model, thanks to the attention paid to the emission of high-energy clusters and to low-energy cluster induced reactions, can be safely used within MCNPX to predict isotopes with a charge larger than that of the target by two units in spallation targets, and, probably, more generally to isotopes created in secondary reactions induced by composite particles.
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