Intranuclear cascade model for a comprehensive description of spallation reaction data

Abstract

A new version of the Liège intranuclear cascade ͑INC͒ model is proposed for the description of spallation reactions. Compared to the previous version, it incorporates new features: ͑i͒ it can accommodate a diffuse nuclear surface, ͑ii͒ the treatment of the Pauli blocking effect is improved, removing unphysical features linked with the use of statistical blocking factors, ͑iii͒ collisions between moving spectator nucleons are explicitly suppressed, ͑iv͒ pion dynamics is improved, especially concerning the delta lifetime, ͑v͒ it can accommodate light ions as incoming projecticles, ͑vi͒ the remnant angular momentum is included in the output of the model. Another important feature is the self-consistent determination of the stopping time, i.e., the time at which the INC calculation is terminated and coupled to evaporation. The predictions of the model, used with the Schmidt evaporation code, are tested against a large body of experimental data, in the 200-MeV-2-GeV range for incident energy per nucleon, including total reaction cross sections, neutron, proton, pion, and composite double differential cross sections, particle multiplicities, residue mass and charge distributions, and residue recoil velocity distributions. Good agreement is generally obtained without additional varying parameters. It is shown that the introduction of a diffuse surface considerably improves the description of the total reaction cross sections, of the intensity of the quasielastic peak in proton and neutron double differential cross sections and of the residue production yield for isotopes close to the target. High energy neutron spectra are found to be sensitive to details of the deuteron structure in deuteron-induced reactions. The shape of the fragmentation peaks in residue mass spectra is shown to be closely related to the shape of the distribution of the excitation energy left after the cascade stage. The longitudinal residue recoil velocity and its fluctuations display typical random-walk characterics, which are interpreted as a direct consequence of the independence of successive binary collisions occurring during the cascade process and therefore provide a strong support of the basic hypotheses of the INC model. Small but systematic discrepancies between model predictions and experiment are identified and possible further improvements to reduce them are discussed. The influence of the evaporation model is investigated. A comparison with similar approaches is presented.

Production of energetic light fragments in extensions of the CEM and LAQGSM event generators of the Monte Carlo transport code MCNP6

“…Figs. 14 and 15 show two examples by this preliminary version of LAQGSM03.03F, namely, spectra of 6,7,8,9 Li at 65 • from proton-gold interactions at 1.2 and 1.9 GeV, respectively. This preliminary version of LAQGSM03.03F describes quite well spectra of all Li fragments measured for these reactions by the PISA collaboration and published in Ref.…”

“…At lower energies, MCNP6 uses tables of evaluated nuclear data (referred to as "data libraries"), while for higher energies (> 150 MeV), MCNP6 uses CEM03.03 and LAQGSM03.03 as mentioned above, as well as by default for some reactions, or when chosen by users, the Bertini intranuclear cascade (INC) [7], ISABEL [8], or the INC developed at Liege (INCL) by Cugnon and colleagues from CEA/Saclay, France, version INCL4.2 [9], merged with the evaporation/fission and Fermi break-up models available in MCNP6 (see details in [1]). Emission of energetic heavy clusters from nuclear reactions plays a critical role in several applications, including electronics performance in space, human radiation dosages in space or other extreme radiation environments, proton and heavy-ion therapy in cancer treatment, accelerator and shielding applications, and more.…”

Extension of the Liège intranuclear cascade model at incident energies between 2 and 12 GeV. Aspects of pion production

“…[4] for a detailed description of the standard version (INCL4.2) of the INCL4 model. It is sufficient here to remind the salient features.…”

“…6 GeV range. A recent intercomparison of models, organized by the IAEA [3], has shown that the intranuclear cascade model developed at the University of Liège, denoted INCL4 [4], coupled to the evaporation-fission ABLA model of K.-H. Schmidt [5,6], can describe quite well a huge body of experimental data for proton-induced reactions in the 100 MeV-2 GeV range. This includes total reaction cross sections, neutron multiplicities, neutron and proton double differential cross sections, residue mass spectra, isotopic distributions and recoil energies.…”

Recent Developments of the Liège Intranuclear Cascade Model in View of its Use into High-energy Transport Codes

“…The Liège Intranuclear Cascade model, INCL4 [1], has originally been developed to describe spallation reactions, i.e. nucleon-induced collisions in the 100 MeV -3 GeV energy range.…”