Nuclear Experiment
- [1] arXiv:2405.15014 [pdf, ps, other]
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Title: Modeling of Deuteron Induced Reactions on Molybdenum at Low EnergiesComments: 31 pages, 25 figuresJournal-ref: Journal of Fusion Energy (2024) 43:15.Subjects: Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
The activities of the EUROfusion consortium on the development of high quality nuclear data for fusion applications include evaluations of deuteron induced reactions and related data libraries for needs of the DEMO fusion power plant and IFMIF-DONES neutron--source nuclear analyses. Molybdenum is one of the major constituents of the reference stainless steels used in critical components of these projects. While the TENDL deuteron data library was the current reference used by EUROfusion, need of its further improvement has already been pointed out. The weak binding energy of the deuteron is responsible for the high complexity of its interaction with nuclei, involving also a variety of reactions initiated by the nucleons following the deuteron breakup. Their analysis completed that of the deuteron interactions with Mo and its stable isotopes, from elastic scattering to pre-equilibrium and compound--nucleus reactions, up to 50 MeV. A particular attention has been paid to the breakup, stripping, and pick-up direct interactions which amount to around half of the deuteron total--reaction cross section. The due account of most experimental data has validated the present approach, highlighted some prevalent features, and emphasized weak points and consequently the need for modeling/evaluation upgrade.
- [2] arXiv:2405.15366 [pdf, ps, html, other]
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Title: Measurement of $\gamma$-rays generated by neutron interaction with ${}^{16}$O at 30 MeV and 250 MeVT. Tano, T. Horai, Y. Ashida, Y. Hino, F. Iacob, A. Maurel, M. Mori, G. Collazuol, A. Konaka, Y. Koshio, T. Nakaya, T. Shima, R. WendellSubjects: Nuclear Experiment (nucl-ex); High Energy Physics - Experiment (hep-ex)
Deep understanding of $\gamma$-ray production from the fast neutron reaction in water is crucial for various physics studies at large-scale water Cherenkov detectors. We performed test experiments using quasi-mono energetic neutron beams ($E_n = 30$ and 250~MeV) at Osaka University's Research Center for Nuclear Physics to measure $\gamma$-rays originating from the neutron-oxygen reaction with a high-purity germanium detector. Multiple $\gamma$-ray peaks which are expected to be from excited nuclei after the neutron-oxygen reaction were successfully observed. We measured the neutron beam flux by using a liquid scintillator for the cross section measurement. With a spectral fitting analysis based on the tailored $\gamma$-ray signal and background templates, we measured cross sections for each observed $\gamma$-ray component. The results will be useful to validate neutron models employed in the on-going and future water Cherenkov experiments.
- [3] arXiv:2405.15601 [pdf, ps, html, other]
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Title: High-resolution spectroscopy of neutron-rich Br isotopes and signatures for a prolate-to-oblate shape transition at N=56J. Dudouet, G. Colombi, D. Reygadas Tello, C. Michelagnoli, D.D. Dao, F. Nowacki, M. Abushawish, E. Clément, C. Costache, G. Duchêne, F. Kandzia, A. Lemasson, N. Marginean, R. Marginean, C. Mihai, S. Pascu, M. Rejmund, K. Rezynkina, O. Stezowski, A. Turturica, S. Ujeniuc, A. Astier, G. de Angelis, G. de France, C. Delafosse, I. Deloncle, A. Gadea, A. Gottardo, P. Jones, T. Konstantinopoulos, I. Kuti, F. Le Blanc, S.M. Lenzi, R. Lozeva, B. Million, R.M. Pérez-Vidal, C.M. Petrache, D. Ralet, N. Redon, C. Schmitt, D. Sohler, D. VerneyComments: 17 pages, 24 figures, 5 tablesSubjects: Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
The first systematic experimental study of the neutron-rich Br isotopes with two complementary state-of-the-art techniques is presented. These isotopes have been populated in the fission process at two different facilities, GANIL and ILL. New spectroscopic information has been obtained for odd-even $^{87-93}$Br isotopes and the experimental results have been compared with state-of-the-art Large-Scale Shell-Model and DNO Shell-Model calculations. As a result of such theoretical approaches, a transition from prolate ($^{87,89}$Br) to oblate ($^{91,93}$Br) shapes is obtained from the subtle balance between proton and neutron quadrupole deformations, as a clear signature of pseudo-SU3 quadrupole regime.
New submissions for Monday, 27 May 2024 (showing 3 of 3 entries )
- [4] arXiv:2405.14884 (cross-list from physics.soc-ph) [pdf, ps, other]
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Title: The story around the first 4n signalComments: Accepted for publication in "Advances on the Few-Body Problem in Physics - Selected and refereed papers from the 25th European Conference"Subjects: Physics and Society (physics.soc-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
The GANIL campaign around the first 4n signal was very peculiar. The beginning and end were both dictated by unexpected events that, unfortunately, do not fit within the streamlined format of standard scientific publications. However, they illustrate many aspects of how basic research should work, or at least does work. Therefore, I take this opportunity to share them with those not involved in the campaign, hoping that they will offer a better perspective of that research in particular and of basic research in general. As a disclaimer, this is only a personal recollection of those events.
- [5] arXiv:2405.15487 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: Principal components of nuclear mass modelsComments: 8 pages, 3 figures, 1 tableJournal-ref: Sci. China Phys. Mech. Astron. 67, 272011 (2024)Subjects: Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
The principal component analysis approach is employed to extract the principal components contained in nuclear mass models for the first time. The effects coming from different nuclear mass models are reintegrated and reorganized in the extracted principal components. These extracted principal components are recombined to build new mass models, which achieve better accuracy than the original theoretical mass models. This indicates that the effects contained in different mass models can work together to improve the nuclear mass predictions with the help of the principal component analysis approach.
- [6] arXiv:2405.15534 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: $K^-d\rightarrow\pi\Lambda N$ reaction with in-flight kaons for studying the $\Lambda N$ interactionComments: 15 pages, 9 figuresSubjects: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
The $\Lambda N$ invariant mass spectra for the reactions $K^-d\rightarrow\pi^-\Lambda p$ and $K^-d\rightarrow\pi^0\Lambda n$ are calculated for experimental study of isospin symmetry breaking in the $\Lambda N$ scattering at low energies, the difference in the scattering lengths and effective ranges of $\Lambda p$ and $\Lambda n$ systems. The calculations are performed for in-flight kaons with a momentum of 1000 MeV/c, employing partial wave analysis up to the p-wave for meson-baryon amplitudes and the spin-flip term for baryon-baryon amplitudes. Kinematic selection is utilized to suppress the background processes, involving the angular selection of pions to the forward direction and selecting nucleons with higher momentum. It is worth noting that isospin symmetry breaking in the $\Lambda N$ system can be extracted from the observed deviations in that breaking in the $\Lambda N$ invariant mass spectra for the $K^-d\rightarrow\pi\Lambda N$ reaction.
- [7] arXiv:2405.15591 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: Constraints for electron-capture decays mimicking production of axion-like particles in nucleiSubjects: Nuclear Theory (nucl-th); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
We give for the first time, theoretical estimates of ground-state-to-ground-state (GS-to-GS) electron-capture (EC) branch decay rates of $^{44}$Ti, $^{57}$Co, and $^{139}$Ce. The nuclear-structure calculations have been done exploiting the nuclear shell model (NSM) with well-established Hamiltonians and an advanced theory of $\beta$ decay. In the absence of experimental measurements of these GS-to-GS branches, these estimates are of utmost importance for terrestrial searches of axion-like particles (ALPs). Predictions are made for EC-decay rates of 2$^{nd}$-forbidden unique (FU) and 2$^{nd}$-forbidden non-unique (FNU) EC transitions that can potentially mimic nuclear axion production in experiments designed to detect ALPs in nuclear environments.
Cross submissions for Monday, 27 May 2024 (showing 4 of 4 entries )
- [8] arXiv:2403.13231 (replaced) [pdf, ps, html, other]
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Title: Design, construction, and operation of a 1-ton Water-based Liquid scintillator detector at Brookhaven National LaboratoryX. Xiang, G. Yang, S. Andrade, M. Askins, D.M. Asner, A. Baldoni, D. Cowen, M.V. Diwan, S. Gokhale, S. Hans, J. Jerome, G. Lawley, S. Linden, G.D. Orebi Gann, C. Reyes, R. Rosero, N. Seberg, M. Smiley, N. Speece-Moyer, B. Walsh, J.J. Wang, M. Wilking, M. YehSubjects: Instrumentation and Detectors (physics.ins-det); High Energy Physics - Experiment (hep-ex); Nuclear Experiment (nucl-ex)
Water-based liquid scintillators (WbLS) are attractive neutrino detector materials because they allow us to tune the ratio of the Cherenkov and scintillation signals. Using WbLS large-scale neutrino experiments can benefit from both directional reconstruction and enhanced low-energy efficiency. Furthermore, broadening the science capability of such materials by metal doping may be better suited for water based liquid scintillators. We recently constructed and commissioned a 1-ton WbLS detector with good photosensor coverage and a capable data acquisition system. We intend to use this flexible detector system as a testbed for WbLS R&D. In this paper we give an overview of the 1-ton system and provide some early analysis results.