0000000000339680
AUTHOR
Isolde Collaboration
Non-analog decay of 74Rb
The magnitude of the Coulomb mixing parameter δ1 IM has been experimentally deduced, for the first time, for the β decay of 74Rb. The estimated magnitude is derived from the feeding of the non-analog first excited 0+ state in 74Kr. The inferred upper limit of 0.07% is small compared to theoretical predictions. The half-life was measured to be 64.90(9) ms. peerReviewed
First decay study of the very neutron-rich isotope 93Br
The decay of the mass-separated, very neutron-rich isotope 93 Br has been studied by γ spectroscopy. A level scheme of its daughter 93 Kr has been constructed. Level energies, γ-ray branching ratios, and multipolarities suggest spins and parities which are in accord with a smooth systematics of the N = 57 isotones for Z <~ 4 0 , suggesting the N = 56 subshell closure still to be effective in Kr isotopes. So far, there is no indication of a progressive onset of deformation in neutron-rich Kr isotopes. peerReviewed
Direct mass measurements on neutron-deficient xenon isotopes with the ISOLTRAP mass spectrometer
The masses of Xe isotopes with 124 A 114 have been measured using the ISOLTRAP spectrometer at the on-line mass separator ISOLDE/CERN. A mass resolving power of 500000 was chosen resulting in an accuracy of m 12 keV for all isotopes investigated. Con icts with existing mass data of several standard deviations were found. peerReviewed
Intruder features in the island of inversion : The 33Mg case
The 33 Na β decay was studied online using mass separation techniques and a first description of the level structure of the neutron-rich isotope 33 Mg , with N = 21 , has been obtained. The experiment involved the measurement of β-γ, β-γ-γ, and β − n − γ coincidences as well as neutron spectra by time-of-flight technique. The first low energy level scheme for the daughter nucleus 33 Mg is given with five bound states. Spin and parity assignments are proposed according to β feedings and γ-ray multipolarities. β-strength distribution is evaluated, taking into account 1 n - and 2 n -emission channels and it is compared with the calculated GT strength distribution. In particular, the 1 p − 1 h …
Proton dripline studies at ISOLDE: 31Ar and 9C
In this contribution examples of the application of new technologies to disentangle the mechanism of beta-delayed multiparticle emission are given. In particular the mechanism of β-delayed two-proton emission from 31Ar has be resolved and proved to be sequential, a preview of 9C-decay data is discussed. peerReviewed
Spectroscopy of 34,35Si by beta decay : sd-fp shell gap and single-particle states
The 34,35Al b decays have been studied at the CERN online mass separator ISOLDE by b-g, b-g-g, and b-n-g measurements in order to corroborate the low-level description of 34Si and to obtain the first information on the level structure of the N521 isotope 35Si. Earlier observed g lines in 34Al decay were confirmed and new g transitions following both b decay and b-delayed neutron emission have been established. The first level scheme of 35Si includes three excited states at 910, 974, and 2168 keV. Indication is found for Jp 5(3/2)2 and (3/2)1 for the first two excited states, respectively. Beta-decay half-life of T1/2538.6(4) ms and b-delayed neutron branching value Pn541(13)% were measured …
Measurement of the Magnetic Moment of the One-Neutron Halo NucleusB11e
The magnetic moment of ${}^{11}\mathrm{Be}$ ( ${T}_{1/2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}13.8\phantom{\rule{0ex}{0ex}}\mathrm{s}$) was measured by detecting nuclear magnetic resonance signals in a beryllium crystal lattice. The experimental technique applied to a ${}^{11}{\mathrm{Be}}^{+}$ ion beam from a laser ion source includes in-beam optical polarization, implantation into a metallic single crystal, and observation of rf resonances in the asymmetric angular distribution of the $\ensuremath{\beta}$ decay ( $\ensuremath{\beta}$-NMR). The nuclear magnetic moment $\ensuremath{\mu}{(}^{11}\mathrm{Be})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}1.6816(8…