Delayed neutron emission probabilities of the precursors89,90,91Br and139,140,141I

Abstract

The delayed neutron emission probabilities of 89'9~ and 139, 140,1411 have been measured. The ions A1Br + and AII+ are formed in the OSIRIS integrated target-ion source giving improved conditions for study of the most neutron-rich isotopes of iodine and bromine. The half-life determinations of 9~ 139I and 141I have been improved.Radioactivity s9 -91Br and 139-141i; measured delayed neutrons and /3-activity; deduced delayed neutron emission probabilities and half-lives

β -decay half-lives of 55 neutron-rich isotopes beyond the N=82 shell gap

“…3. The experimental results are compared with literature values [23,[29][30][31][32][33][34][35][36][37][38] and five theoretical predictions: finite-range droplet-model FRDM-1995 mass formula [46] with quasiparticle-randomphase approximation (QRPA) (2003) [39] as well as the new version (2019) [40] with FRDM-2012 masses [47], Koura-Tachibana-Uno-Yamada (KTUY) with the second generation of β-decay gross theory (GT2) [41,42], Relativistic Hartree-Bogoliubov (RHB) with the proton-neutron relativistic quasiparticle random-phase approximation (pn-RQRPA) [43], and the energy density functional (DF) with continuum quasiparticle random-phase approximation (CQRPA) [44,45].…”

“…One reason for the discrepancy is that the Q β values in this calculation do not include pairing effects. The DF+CQRPA are only applicable for nearly spherical nuclei, so they fit well [23,[29][30][31][32][33][34][35][36][37][38]. The measurements are compared to predictions of five theoretical models: FRDM+QRPA (2003) [39] (brown), FRDM+QRPA (2019) [40] (green), KTUY+GT2 [41,42] (red), RHB+pn-RQRPA [43] (blue), and DF+CQRPA [44,45] (magenta).…”

The beta decay of139I

“…1391. Experiments at OSIRIS and Lohengrin were hindered by the high activity of the longer-lived isobars in the mass separated samples [4][5][6]. In contrast, the negativesurface ionization source produced samples of both 1391 and 1401 free from any isobaric and/or isotopic contamination.…”

$β$-Decay Half-Lives of 55 Neutron-Rich Isotopes beyond the N=82 Shell Gap

“…3. The experimental results are compared with literature values [23][24][25][26][27][28][29][30][31][32][33] and five theoretical predictions: finite-range droplet-model FRDM-1995 mass formula [46] with quasi-particle-random-phase approximation (QRPA) (2003) [34] as well as the new version (2019) [35] with FRDM-2012 masses [47], Koura-Tachibana-Uno-Yamada (KTUY) with the second generation of β-decay gross theory (GT2) [36,37], Relativistic Hartree-Bogoliubov (RHB) with the proton-neutron Relativistic quasiparticle random phase approximation (pn-RQRPA) [38], and the energy density functional (DF) with continuum quasi-particle random-phase approximation (CQRPA) [39,40].…”