$β$-delayed neutron spectroscopy of $^{85, 86}$As with MONSTER at IGISOL

A. Pérez de Rada Fiol; T. Martínez; D. Cano-Ott; H. Penttilä; J. Agramunt; V. Alcayne; A. Algora; S. Alhomaidhi; J. Äystö; K. Banerjee; O. Beliuskina; J. Benito; C. Bhattacharya; F. Calviño; G. Cortés; R. P. de Groote; A. de Roubin; C. Delafosse; C. Domingo-Pardo; S. Geldhof; W. Gins; M. Hukkanen; A. Jokinen; A. Kankainen; J. Lerendegui-Marco; J. Llanes Gamonoso; I. Matea; E. Mendoza; A. K. Mistry; D. A. Nesterenko; J. Plaza; I. Pohjalainen; S. Rinta-Antila; P. Roy; A. Sanchez-Caballero; J. L. Taín; D. Villamarín; M. Vilen

doi:10.1103/physrevc.111.044312

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arXiv · 2501.18285

$β$-delayed neutron spectroscopy of $^{85, 86}$As with MONSTER at IGISOL

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Abstract

The $β$-delayed neutron emission in the $^{85, 86}$As $β$-decays has been measured at the Ion Guide Isotope Separator On Line facility of the Accelerator Laboratory of the University of Jyväskylä. The complete $β$-decays have been studied with a complex setup that consists of a plastic scintillator for $β$-particles, MONSTER -- the MOdular Neutron time-of-flight SpectromeTER -- for neutrons, and a high-purity germanium and four LaBr$_3$ crystals for $γ$-rays. The $β$-delayed neutron energy distributions have been determined by unfolding the time-of-flight spectra with an innovative methodology based on the iterative Bayesian unfolding method and accurate Monte Carlo simulations. The results obtained for $^{85}$As are in excellent agreement with the existing evaluated data, validating the proposed methodology. In the case of $^{86}$As, a stronger neutron intensity at higher energies than previously predicted is discovered.

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A. Pérez de Rada Fiol, T. Martínez, D. Cano-Ott, H. Penttilä, J. Agramunt, V. Alcayne, A. Algora, S. Alhomaidhi, J. Äystö, K. Banerjee, O. Beliuskina, J. Benito, C. Bhattacharya, F. Calviño, G. Cortés, R. P. de Groote, A. de Roubin, C. Delafosse, C. Domingo-Pardo, S. Geldhof, W. Gins, M. Hukkanen, A. Jokinen, A. Kankainen, J. Lerendegui-Marco, J. Llanes Gamonoso, I. Matea, E. Mendoza, A. K. Mistry, D. A. Nesterenko, J. Plaza, I. Pohjalainen, S. Rinta-Antila, P. Roy, A. Sanchez-Caballero, J. L. Taín, D. Villamarín, M. Vilen. 2025-03-13. $β$-delayed neutron spectroscopy of $^{85, 86}$As with MONSTER at IGISOL. https://doi.org/10.1103/physrevc.111.044312

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