The β-delayed neutron emission in the ^85,86As β-decays has been measured at the IGISOL facility of the Accelerator Laboratory of the University of Jyväskylä (JYFL-ACCLAB). The complete β-decays have been studied with a complex setup that consists of a plastic scintillator, the MOdular Neutron time-of-flight SpectromeTER (MONSTER), and two types of γ-ray detectors—an HPGe clover and four LaBr₃ crystals. The β-delayed neutron energy distributions have been determined by unfolding the TOF spectra with an innovative methodology based on the iterative Bayesian unfolding method and accurate Monte Carlo simulations.

The β -delayed neutron emission in the As 85 , 86 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 As 85 are in excellent agreement with the existing evaluated data, validating the proposed methodology. In the case of As 86 , a stronger neutron intensity at higher energies than previously predicted is discovered.

The β-delayed neutron emission in the 85As β-decay has been measured at the IGISOL facility of the Accelerator Laboratory of the University of Jyväskylä (JYFL). The complete β-decay has been studied with a setup which consists of a plastic scintillator, the MOdular Neutron time-of-flight SpectromeTER (MONSTER), and two types of γ-rays detectors (HPGe and LaBr3). The, β-delayed neutron energy distribution has been determined by unfolding the TOF spectrum with the iterative Bayesian unfolding method.