Speaker
Description
Modern theoretical studies and industrial applications related to the design, radiation protection, and reliability of nuclear facilities, medical applications, as well as space research and exploration are relying on extensive simulations and modeling. Computer codes realizing various semi-classical and quantum molecular dynamics (QMD) approaches are often employed to make up for the lack of accelerator data on many nuclear reactions at intermediate and high energies (above 10s of MeV per nucleon) and are in high demand nowadays.
This contribution focuses on the methodology of generating reliable proton-induced cross section data on $^{56}$Fe nucleus required for activation analysis and other applications in the energy range below 10 GeV. We developed a problem-oriented computer framework based on MCNPX [1] and CASCADE/INPE [2] codes to calculate activation cross section data at intermediate and high energies. Goodness of the fits of nucleon-nucleus interaction models to the existing data is evaluated based on elaborated algorithms. The method is based on the analysis of a large set of experimental data and calculated cross sections for $^{56}$Fe and different residual nuclei in a wide range of energies of incident protons using numerous coincidence criteria.
In practice, this could be done in different ways. One way is tuning the model parameters and algorithms to fit required experimental data subset. Another way is to try to achieve unification and consistency of fundamental parameters for all considered reactions. The presented framework is pursuing the latter approach. We use proton-induced reactions on $^{56}$Fe nucleus to illustrate the application of the developed multi-criteria algorithm, where we use all reaction cross section data below 10 GeV available from the EXFOR experimental data library and the IAEA CRP "Benchmark of Spallation Models." We demonstrate that the analysis of the predictive power of various intermediate and high-energy models based on the multi-criteria algorithm allows more sophisticated selection of appropriate models in a given energy range and target nuclei domain.
The major obstacle in improving an accuracy of the nuclear codes is the scarcity of the available measurements. We are aiming at using the NICA facility (Nuclotron-based Ion Collider fAcility) [3] – a new accelerator complex at the Joint Institute for Nuclear Research (JINR, Dubna, Russia). NICA will provide variety of beam species from p to Au ions. Heavy ions will be accelerated up to kinetic energy of 4.5 GeV/nucleon, protons – up to 12.6 GeV.
Measurements of the isotopic cross sections will be conducted using proton and ion beams and thin targets. Besides, NICA can be used for studies of secondary neutron and γ-ray emission – of interest for simulations of the radiation environment at the rocky surfaces of planets and asteroids. New data will be used to tune models of nuclear reactions and for astrophysical applications.
Acknowledgements: IVM acknowledges support from NASA grant No. NNX17AB48G.
References:
[1] D. B. Pelowitz, et al., "MCNPX 2.7.0 Extensions", LA-UR-11-02295 (2011).
[2] V.S. Barashenkov, A.Y. Konobeyev, Y.A. Korovin, V.N. Sosnin, At. Energy 87 (4)(1999) 742.
[3] E.Syresin et al., NICA accelerator complex at JINR, Proc. IPAC2019, Melbourne, Australia, doi:10.18429/JACoW-IPAC2019-MOPMP01; https://nica.jinr.ru/