arXiv subjects

Marc Dupuis

Publications and source records attributed to Marc Dupuis.

7 recordsLinked to original sources

arXiv2026

Gogny interaction from beginnings to current challenges

The main goal of the present review article is to gather for the first time various facets of the phenomenological effective Gogny interaction which was originally proposed in the 70's. This involves both nuclear phenomena of interest that led to its creation and evolution as well as highly technical aspects that led the objectives to be achieved. With this in mind, we propose a discussion structured around four points. After a general introduction, the history and philosophy of the Gogny interaction is exposed. In particular, one highlights an intuitive way of guiding the determination of the parameters of the phenomenological interaction with the results obtained from a realistic interaction using Hartree-Fock calculations and second order corrections and a G-matrix. One also shows that physical phenomena such as pairing or fission were essential to improve the parameterization. The evolution of the original analytical form over the years is also discussed. The second point concern the emulator that was used for the generation of parameterizations. Its modifications, consistent with the evolution of the analytical form, are given. Other fitting procedures, more recent, are also evoked. The third key point is dedicated to the role of the nuclear matter in the fitting process and the acceptance of a parameterization. The objective of the last key point is to highlight some results obtained with the Gogny interaction in nuclear structure, fission and reactions that have allowed to interpret experimental data.

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arXiv2026

Surrogate neutron-capture studies with fission detection in inverse kinematics at the ESR storage ring

The NECTAR (Nuclear rEaCTions At storage Rings) experiment at the ESR heavy-ion storage ring at GSI/FAIR Darmstadt is dedicated to surrogate reaction studies of neutron-induced reactions on heavy nuclei in inverse kinematics. In this work, we report on the implementation and performance of a newly developed fission-fragment detection system integrated into the NECTAR experimental setup. The upgraded detector configuration enables, for the first time in a surrogate experiment, the simultaneous detection ofgamma-decay residues, multi-neutron-emission residues, and fission fragments. The full setup was used for the first time in an experiment where a stored beam of bare 238U92+ ions at 17.24 MeV/u interacted with a gas-jet deuterium target, populating excited 238U and 239U nuclei via the 238U(d,d') and 238U(d,p) reactions. We describe the geometry of the used fission fragment detectors, design constraints, and simulation-based efficiency determination. The target-like particle identification and beam-like residue spectra demonstrating the performance of the complete setup are also shown.

physics.ins-det↗

arXiv2025

Constraining capture cross sections using proton inelastic scattering as a surrogate reaction

The surrogate reaction method is an alternative to direct measurements of compound nuclear reaction cross sections. We introduce theory tools for extracting capture cross sections from experiments that use proton inelastic scattering as a surrogate reaction mechanism. This makes it possible to constrain compound nucleus decay models which are typically the largest source of uncertainty in capture cross section calculations. This letter describes the theory developments that were used to simultaneously infer $^{89}$Y$(p,\gamma)$ and $^{89}$Zr$(n,\gamma)$ cross sections from $^{90}$Zr$(p,p'\gamma)$ surrogate measurements.

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arXiv2025

Modeling direct and pre-equilibrium processes of neutron-induced reactions with noniterative finite amplitude method and distorted-wave Born approximation

We develop a calculation method for describing the direct and pre-equilibrium processes in neutron-induced reactions based on the framework of noniterative finite amplitude method (FAM) and distorted-wave Born approximation (DWBA). The noniterative FAM is used to derive equations of quasiparticle random-phase approximation (QRPA) for neutron-induced inelastic scatterings to both the discrete and continuum states in a consistent manner. The Skyrme force is employed as an interaction between the projectile neutron with nucleons inside the target nucleus. We apply this method to the neutron-induced reaction on 208Pb. We demonstrate that the calculated differential inelastic scattering cross sections to low-lying states reproduce available experimental data without any phenomenological parameters that are often introduced in conventional DWBA calculations. The calculated double differential cross section to the continuum state also agrees with the experimental data in the energy region relevant to the direct and pre-equilibrium processes. These results are used to investigate the spin distribution of the populated states in the residual nucleus.

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arXiv2024

Predicting nucleon-nucleus scattering observables using nuclear structure theory

Developing a predictive capability for inelastic scattering will find applications in multiple areas. Experimental data for neutron-nucleus inelastic scattering is limited and thus one needs a robust theoretical framework to complement it. Charged-particle inelastic scattering can be used as a surrogate for $(n, \gamma)$ reactions to predict capture cross sections for unstable nuclei. Our work uses microscopic nuclear structure calculations for spherical nuclei to obtain nucleon-nucleus scattering potentials and calculate cross sections for these processes. We implement the Jeukenne, Lejeune, Mahaux (JLM) semi-microscopic folding approach, where the medium effects on nuclear interaction are parameterized in nuclear matter to obtain the nucleon-nucleon $(NN)$ interaction in a medium at positive energies. We solve for the nuclear ground state using the Hartree-Fock-Bogliubov (HFB) many-body method, assuming the nucleons within the nucleus interact via the Gogny-D1M potential. The vibrational excited states of the target nucleus are calculated using the quasi-particle random phase approximation (QRPA). We demonstrate our approach for spherical nuclei in the medium-mass region, showing scattering results for the $^{90}$Zr nucleus.

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arXiv2021

Oscillating currents stabilize aluminium cells for efficient, low carbon production

Humankind produced 63.7 million metric tons of aluminium in 2019, nearly all via an electrochemical process in which electrical current liberates molten Al from dissolved alumina. That year, Al production required 848 TWh of electricity1, 3% of the worldwide total, and caused 1% of human greenhouse gas emissions. Much of the electricity and emissions originate from energy loss in the poorly conducting electrolyte where aluminum oxide is dissolved. Thinning the electrolyte layer could decrease loss but has been limited by the Metal Pad Instability (MPI), which causes Al cells to slosh out of control if the electrolyte is not sufficiently thick. Here we show that adding an oscillating component to the current disrupts the MPI in realistic simulations, allowing stable operation with electrolyte layers at least 12% thinner. This occurs when oscillation excites standing waves, which decouple the resonance that drives a growing traveling wave, characteristic of the MPI. Maintaining oscillation can prevent MPI; initiating oscillation can halt an MPI in progress. Our findings could significantly increase the efficiency of virtually all aluminium refining cells without the need for expensive reconstruction, thereby decreasing energy use by 34 TWh/year (2.1 MJ/kg Al) or more and greenhouse gas emissions by 13 Mton/year or more.

physics.flu-dyn↗

arXiv2010

Particle-particle random phase approximation applied to Beryllium isotopes

This work is dedicated to the study of even-even 8-14 Be isotopes using the particle-particle Random Phase Approximation that accounts for two-body correlations in the core nucleus. A better description of energies and two-particle amplitudes is obtained in comparison with models assuming a neutron closed-shell (or subshell) core. A Wood-Saxon potential corrected by a phenomenological particle-vibration coupling term has been used for the neutron-core interaction and the D1S Gogny force for the neutron-neutron interaction. Calculated ground state properties as well as excited state ones are discussed and compared to experimental data. In particular, results suggest the same 2s_1/2-1p_1/2 shell inversion in 13Be as in 11Be.

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