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New half-lives for exotic isotopes approaching the neutron drip-line in the vicinity of N∼28 for Z=12-15 were measured at the Facility for Rare Isotope Beams (FRIB) with the FRIB decay station initiator. The first experimental results are compared to the latest quasiparticle random phase approximation and shell-model calculations. Overall, the measured half-lives are consistent with the available theoretical descriptions and suggest a well-developed region of deformation below ^{48}Ca in the N=28 isotones. The erosion of the Z=14 subshell closure in Si is experimentally confirmed at N=28, and a reduction in the ^{38}Mg half-life is observed as compared with its isotopic neighbors, which does not seem to be predicted well based on the decay energy and deformation trends. This highlights the need for both additional data in this very exotic region, and for more advanced theoretical efforts.

At the RIKEN Nishina Center, exotic neutron-rich isotopes of Ba, La, Ce, Pr, and Nd were measured. This work reports their half-lives (T1/2) and β-delayed neutron-emission probabilities (Pxn). The setup consisted of the BigRIPS in-flight separator for particle identification, the Advanced Implantation Detector Array (AIDA) for ions and β detection, and the BRIKEN neutron counter for neutron detection. Using this arrangement, 4 new T1/2 and 14 new P1n were measured. Furthermore, 38 T1/2 and 2 P1n values were remeasured, decreasing the uncertainties for some of them. In addition to improving predictions of nucleosynthesis models that describe the production of the rare-earth peak at A ∼ 160 via the r-process, these additional experimental data should help to constrain theoretical models for calculations of T1/2 and Pxn in this region.

The β-delayed neutron-emission probabilities of 28 exotic neutron-rich isotopes of Pm, Sm, Eu, and Gd were measured for the first time at RIKEN Nishina Center using the Advanced Implantation Detector Array (AIDA) and the BRIKEN neutron detector array. The existing β-decay half-life (T 1/2) database was significantly increased toward more neutron-rich isotopes, and uncertainties for previously measured values were decreased. The new data not only constrain the theoretical predictions of half-lives and β-delayed neutron-emission probabilities, but also allow for probing the mechanisms of formation of the high-mass wing of the rare-earth peak located at A ≈ 160 in the r-process abundance distribution through astrophysical reaction network calculations. An uncertainty quantification of the calculated abundance patterns with the new data shows a reduction of the uncertainty in the rare-earth peak region. The newly introduced variance-based sensitivity analysis method offers valuable insight into the influence of important nuclear physics inputs on the calculated abundance patterns. The analysis has identified the half-lives of 168Sm and of several gadolinium isotopes as some of the key variables among the current experimental data to understand the remaining abundance uncertainty at A = 167–172.

The $\ensuremath{\beta}$ decay of $^{125m,125}\mathrm{Ag}$ into levels in $^{125}\mathrm{Cd}$ was investigated at the Holifield Radioactive Ion Beam Facility (HRIBF). Uranium-238 targets were bombarded with 50-MeV protons with an intensity of $15\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}$A, and the induced fission products were mass separated and deposited on a moving tape in the center of the VANDLE array consisting of $\ensuremath{\gamma}$ detectors and plastic scintillators. A partial decay scheme has been assigned for both $\ensuremath{\beta}$ decay of the (9/${2}^{+}$) ground state of $^{125}\mathrm{Ag}$ and its low-lying (1/${2}^{\ensuremath{-}}$) isomer, with the energy of the low-lying (11/${2}^{\ensuremath{-}}$) isomeric state in $^{125}\mathrm{Cd}$ assigned as 188.5 keV. In addition, $\ensuremath{\beta}$-delayed neutron emission probabilities were also determined to be 1.2(2)% for the (9/${2}^{+}$) $^{125}\mathrm{Ag}$ ground state and 4.6(10)% for the (1/${2}^{\ensuremath{-}}$) isomer, which are substantially lower than the previously reported value.

The structure of Po-208 populated through the EC/beta(+) decay of At-208 is investigated using gamma-ray spectroscopy at the ISOLDE Decay Station. The presented level scheme contains 27 new excited states and 43 new transitions, as well as a further 50 previously observed. rays which have been (re)assigned a position. The level scheme is compared to shell model calculations. Through this analysis approximately half of the beta-decay strength of At-208 is found to proceed via allowed decay and half via first-forbidden decay. The first-forbidden transitions predominantly populate core excited states at high excitation energies, which is qualitatively understood using shell model considerations. This mass region provides an excellent testing ground for the competition between allowed and first-forbidden beta-decay calculations, important for the detailed understanding of the nucleosynthesis of heavy elements.

16 pags., 9 figs., 7 tabs., In an experiment performed at the SPIRAL1 facility of GANIL, the β decay of Ar has been studied by means of the “Silicon Cube” device associated with germanium clover detectors from the EXOGAM array. Beta-delayed protons and γ rays have been observed and allowed the determination of all relevant decay branches. The Gamow–Teller strength distribution is compared to shell-model calculations and excellent agreement is found. The Fermi strength is inline with expectations. A quasi-complete decay scheme of Ar is established., This work was partly funded by the Conseil régional de la Nouvelle Aquitaine and the EU through the Human Capital and Mobility program. We acknowledge support from CICYT via contract FPA2007-62179. BAB is supported by NSF via Grant PHY1811855.

We determine for the first time the magnetic dipole moment of a short-lived nucleus with part-per-million (ppm) accuracy. To achieve this 2-orders-of-magnitude improvement over previous studies, we implement a number of innovations into our β-detected nuclear magnetic resonance (β-NMR) setup at ISOLDE at CERN. Using liquid samples as hosts, we obtain narrow, subkilohertz-linewidth, resonances, while a simultaneous in situ 1H NMR measurement allows us to calibrate and stabilize the magnetic field to ppm precision, thus eliminating the need for additional β-NMR reference measurements. Furthermore, we use ab initio calculations of NMR shielding constants to improve the accuracy of the reference magnetic moment, thus removing a large systematic error. We demonstrate the potential of this combined approach with the 1.1 s half-life radioactive nucleus 26Na, which is relevant for biochemical studies. Our technique can be readily extended to other isotopic chains, providing accurate magnetic moments for many short-lived nuclei. Furthermore, we discuss how our approach can open the path toward a wide range of applications of the ultrasensitive β-NMR in physics, chemistry, and biology. ispartof: Physical Review X vol:10 issue:4 status: Published online

Background: Neutron-rich nuclei in the mass region around A=160 have been and will continue to be of interest for the study of nuclear structure because of the rapid onset of deformation between 88 and 90 neutrons. The observation of detailed changes in nuclear structures within this mass region has provided and will continue to provide insight into the nuclear force. Purpose: Investigations of γ rays emitted following Eu163 β-decay to Gd163 have been performed for evaluation of the nuclear structure of Gd163. Method: Data were collected at the LeRIBSS station of the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory with an array of four Clover HPGe detectors for γ-rays and two plastic scintillators for β detection. The γ rays were identified as belonging to Gd163 via mass selection and γ-γ-β, x-ray-γ, or γ-γ coincidences. Results: In total 107 new γ-ray transitions were observed in Gd163 from 53 newly identified levels. Conclusions: The structure of Gd163 has been identified for the first time. This structure has been evaluated in comparison to projected shell model, and potential energy surface calculations with good agreement.

Recently there has been an increased interest to apply the sensitive β-decay asymmetry detected nuclear magnetic resonance (β-NMR) technique to biological studies. A liquid-sample β-NMR setup was build at ISOLDE to allow such investigations and to use the resolution gain of liquid-state NMR in nuclear physics. As part of this setup a magnetic field locking system, a set of printed circuit board shimming coils, a sample exchange system, a set of compact β-detectors and a custom experimental vacuum chamber were developed. The main magnetic field was stabilized down to the ppm level by the locking system while allowing the direct determination of the absolute magnetic field. The homogeneity of the magnetic field was improved to ≤ 5 ppm over the sample volume by the shimming coils. Time spent on changing samples was reduced by a factor of five by the liquid sample exchange system. During experiments it was possible to continuously observe the liquid sample thanks to the custom chamber and compact β-detectors. The absolute field determination allows for a novel way to reference β-NMR measurements, removing the need for time consuming reference measurements. The improved accuracy and resolution resulting from these innovations allows the study of the distribution of nuclear magnetization and (bio)chemicals using high-accuracy liquid-sample β-NMR. Recently there has been an increased interest to apply the sensitive $\beta$-decay asymmetry detected nuclear magnetic resonance ($\beta$-NMR) technique to biological studies. A liquid-sample $\beta$-NMR setup was build at ISOLDE to allow such investigations and to use the resolution gain of liquid-state NMR in nuclear physics. As part of this setup a magnetic field locking system, a set of printed circuit board shimming coils, a sample exchange system, a set of compact $\beta$-detectors and a custom experimental vacuum chamber were developed. The main magnetic field was stabilized down to the ppm level by the locking system while allowing the direct determination of the absolute magnetic field. The homogeneity of the magnetic field was improved to $\leq$~5~ppm over the sample volume by the shimming coils. Time spent on changing samples was reduced by a factor of five by the liquid sample exchange system. During experiments it was possible to continuously observe the liquid sample thanks to the custom chamber and compact $\beta$-detectors. The absolute field determination allows for a novel way to reference $\beta$-NMR measurements, removing the need for time consuming reference measurements. The improved accuracy and resolution resulting from these innovations allows the study of the distribution of nuclear magnetization and (bio)chemicals using high-accuracy liquid-sample $\beta$-NMR.

Spin–isospin excitations in Nb 100 were studied via the Mo 100 ( t , He 3 ) charge-exchange reaction at 115 MeV/u with the goal to constrain theoretical models used to describe the isovector spin response of nuclei. The experiment was performed with a secondary beam of tritons, and 3He particles were analyzed in the S800 magnetic spectrometer. Decay by neutron emission from excited states in Nb 100 was observed by using plastic and liquid scintillator arrays. Differential cross sections were analyzed and monopole excitations were revealed by using a multipole decomposition analysis. The Gamow–Teller transition strength observed at low excitation energies, which is important for estimating the electron-capture rate in astrophysical scenarios, was strongly fragmented and reduced compared to single-particle and spherical mean-field models. The consideration of deformation in the theoretical estimates was found to be important to better describe the fragmentation and strengths. A strong excitation of the isovector spin giant monopole resonance was observed, and well reproduced by the mean-field models. Its presence makes the extraction of Gamow–Teller strengths at high excitation energies difficult. The branches for statistical and direct decay by neutron emission were identified in the spectra. The upper limit for the branching ratio by direct decay (integrated over all observed excitations) was determined to be 20 ± 6 % . Even though the statistical uncertainties in the neutron-coincident data were too large to perform detailed studies of the decay by neutron emission from individual states and resonances, the experiment demonstrates the feasibility of the method.

Aquesta es una copia de la versio author’s final draft d'un article publicat a la revista [Physical Review C ]. URL d'aquest document a UPCommons E-prints: http://hdl.handle.net/2117/174873

The structure of $^{34}$Si was studied through $\gamma$ spectroscopy separately in the $\beta^-$ decays of $^{34}$Mg and $^{34}$Al at the ISOLDE facility of CERN. Different configurations in $^{34}$Si were populated independently from the two recently identified $\beta$-decaying states in $^{34}$Al having spin-parity assignments $J^\pi = 4^-$ dominated by the normal configuration $\pi (d_{5/2})^{-1} \otimes \nu (f_{7/2})$ and $J^\pi = 1^+$ by the intruder configuration $\pi (d_{5/2})^{-1} \otimes \nu (d_{3/2})^{-1}(f_{7/2})^{2}$. The paper reports on spectroscopic properties of $^{34}$Si such as an extended level scheme, spin and parity assignments based on log($ft$) values and $\gamma$-ray branching ratios, absolute $\beta$ feeding intensities and neutron emission probabilities. A total of 11 newly identified levels and 26 transitions were added to the previously known level scheme of $^{34}$Si. Large scale shell-model calculations using the {\sc sdpf-u-mix} interaction, able to treat higher order intruder configurations, are compared with the new results and conclusions are drawn concerning the predictive power of {\sc sdpf-u-mix}, the $N=20$ shell gap, the level of mixing between normal and intruder configurations for the 0$_1^+$, 0$_2^+$ and 2$_1^+$ states and the absence of triaxial deformation in $^{34}$Si.

11 pags., 9 figs., 3 tabs. -- Open Access funded by Creative Commons Atribution Licence 4.0, We report on the development and characterization of the first radioactive boron beams produced by the isotope mass separation online (ISOL) technique at CERN-ISOLDE. Despite the long history of the ISOL technique which exploits thick targets, boron beams have up to now not been available. This is due to the low volatility of elemental boron and its high chemical reactivity which make the definition of an appropriate production target unit difficult. In addition, the short half-lives of all boron radioisotopes complicate tracer release studies. We report here on dedicated offline release studies by neutron capture and alpha detection done with implanted B in prospective target materials, as well as molecule formation and ionization tests, which suggested the use of multiwalled carbon nanotubes (CNT) as target material and injection of sulfur hexafluoride SF to promote volatile boron fluoride formation. Two target units equipped with an arc discharge electron impact ion source VADIS coupled to a water cooled transfer line to retain non-volatile elements and molecules were subsequently tested online. The measured yield of these first B ISOL beams increases in the series BF < BF < B < BF , reaching a maximum yield of 6. 4 × 10 BF ions per μC of protons., This work has been partly supported by the Spanish CICYT through projects, FPA2015-64969-P, and by the European Union by means of the European Commission within its Seventh Framework Program (FP7) via ENSAR (Contract No. 262010). Further, this project has received funding from the European Union Horizon 2020 research and innovation program under grant agreement No. 654002. One of the authors, CS, acknowledges support by the German BMBF via the Gentner program and his local project 05P12RDCIA.

The Versatile Array of Neutron Detectors at Low Energy (VANDLE) is a new, highly efficient plastic-scintillator array constructed for decay and transfer reaction experimental setups that require neutron detection. The versatile and modular design allows for customizable experimental setups including beta-delayed neutron spectroscopy and (d,n) transfer reactions in normal and inverse kinematics. The neutron energy and prompt-photon discrimination is determined through the time of flight technique. Fully digital data acquisition electronics and integrated triggering logic enables some VANDLE modules to achieve an intrinsic efficiency over 70% for 300-keV neutrons, measured through two different methods. A custom Geant4 simulation models aspects of the detector array and the experimental setups to determine efficiency and detector response. A low detection threshold, due to the trigger logic and digitizing data acquisition, allowed us to measure the light-yield response curve from elastically scattered carbon nuclei inside the scintillating plastic from incident neutrons with kinetic energies below 2 MeV.

Decay of $^{85}\mathrm{Ga}$ was studied by means of $\ensuremath{\beta}$-neutron-$\ensuremath{\gamma}$ spectroscopy. A pure beam of $^{85}\mathrm{Ga}$ was produced at the Holifield Radioactive Ion Beam Facility using a resonance ionization laser ion source and a high-resolution electromagnetic separator. The $\ensuremath{\beta}$-delayed neutron emission probability was measured for the first time, yielding 70(5)%. An upper limit of 0.1% for $\ensuremath{\beta}$-delayed two-neutron emission was also experimentally established for the first time. A detailed decay scheme including absolute $\ensuremath{\gamma}$-ray intensities was obtained. Results are compared with theoretical $\ensuremath{\beta}$-delayed emission models.

A new detection system has been installed at the RIKEN Nishina Center (Japan) to investigate decay properties of very neutron-rich nuclei. The setup consists of three main parts: a moderated neutron counter , a detection system sensitive to the implantation and decay of radioactive ions, and γ -ray detectors. We describe here the setup, the commissioning experiment and some selected results demonstrating its performance for the measurement of half-lives and β -delayed neutron emission probabilities. The methodology followed in the analysis of the data is described in detail. Particular emphasis is placed on the correction of the accidental neutron background.

6 pags., 3 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0. -- Presented at the XXXV Mazurian Lakes Conference on Physics, Piaski, Poland, September 3–9, 2017., Excited states in the neutron-rich isotope 133Sn were studied via the ß decay of 133In. Isomer selective ionization using the ISOLDE RILIS enabled the ß decays of 133Ings (I¿ = 9=2+) and 133mIn (II¿ = 1=2-) to be studied independently for the first time. A description of the experimental setup at the ISOLDE Decay Station is presented together with preliminary results from the experiment., This work was supported in part by the National Science Centre, Poland (NCN) under contracts No. UMO-2015/18/E/ST2/00217 and No. UMO- 2015/18/M/ST2/00523, by the Spanish MINECO via FPA2015-65035-P project and by the Portuguese FCT via CERN/FIS-NUC/0004/2015 project.

We report the results of a β-decay study of fission products ^{86}Br, ^{89}Kr, ^{89}Rb, ^{90gs}Rb, ^{90m}Rb, ^{90}Kr, ^{92}Rb, ^{139}Xe, and ^{142}Cs performed with the Modular Total Absorption Spectrometer (MTAS) and on-line mass-separated ion beams. These radioactivities were assessed by the Nuclear Energy Agency as having high priority for decay heat analysis during a nuclear fuel cycle. We observe a substantial increase in β feeding to high excited states in all daughter isotopes in comparison to earlier data. This increases the average γ-ray energy emitted by the decay of fission fragments during the first 10 000 s after fission of ^{235}U and ^{239}Pu by approximately 2% and 1%, respectively, improving agreement between results of calculations and direct observations. New MTAS results reduce the reference reactor ν[over ¯]_{e} flux used to analyze reactor ν[over ¯]_{e} interaction with detector matter. The reduction determined by the ab initio method for the four nuclear fuel components, ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu, amounts to 0.976, 0.986, 0.983, and 0.984, respectively.

Background: An assessment done under the auspices of the Nuclear Energy Agency in 2007 suggested that the $\ensuremath{\beta}$ decays of abundant fission products in nuclear reactors may be incomplete. Many of the nuclei are potentially affected by the so called pandemonium effect and their $\ensuremath{\beta}\text{\ensuremath{-}}\ensuremath{\gamma}$ decay heat should be restudied using the total absorption technique. The fission products $^{137}\mathrm{I}$ and $^{137}\mathrm{Xe}$ were assigned highest priority for restudy due to their large cumulative fission branching fractions. In addition, measuring $\ensuremath{\beta}$-delayed neutron emission probabilities is challenging and any new technique for measuring the $\ensuremath{\beta}$-neutron spectrum and the $\ensuremath{\beta}$-delayed neutron emission probabilities is an important addition to nuclear physics experimental techniques.Purpose: To obtain the complete $\ensuremath{\beta}$-decay pattern of $^{137}\mathrm{I}$ and $^{137}\mathrm{Xe}$ and determine their consequences for reactor decay heat and ${\overline{\ensuremath{\nu}}}_{e}$ emission. Complete $\ensuremath{\beta}$-decay feeding includes ground state to ground state $\ensuremath{\beta}$ feeding with no associated $\ensuremath{\gamma}$ rays, ground state to excited states $\ensuremath{\beta}$ transitions followed by $\ensuremath{\gamma}$ transitions to the daughter nucleus ground state, and $\ensuremath{\beta}$-delayed neutron emission from the daughter nucleus in the case of $^{137}\mathrm{I}$.Method: We measured the complete $\ensuremath{\beta}$-decay intensities of $^{137}\mathrm{I}$ and $^{137}\mathrm{Xe}$ with the Modular Total Absorption Spectrometer at Oak Ridge National Laboratory. We describe a technique for measuring the $\ensuremath{\beta}$-delayed neutron energy spectrum, which also provides a measurement of the $\ensuremath{\beta}$-neutron branching ratio, ${P}_{n}$.Results: We validate the current Evaluated Nuclear Structure Data File (ENSDF) evaluation of $^{137}\mathrm{Xe}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$ decay. We find that major changes to the current ENSDF assessment of $^{137}\mathrm{I}\ensuremath{\beta}$-decay intensity are required. The average $\ensuremath{\gamma}$ energy per $\ensuremath{\beta}$ decay for $^{137}\mathrm{I}\ensuremath{\beta}$ decay ($\ensuremath{\gamma}$ decay heat) increases by 19%, from 1050--1250 keV, which increases the average $\ensuremath{\gamma}$ energy per $^{235}\mathrm{U}$ fission by $0.11%$. We measure a $\ensuremath{\beta}$-delayed neutron branching fraction for $^{137}\mathrm{I}\ensuremath{\beta}$ decay of $7.9\ifmmode\pm\else\textpm\fi{}0.2(\mathrm{fit})\ifmmode\pm\else\textpm\fi{}0.4(\mathrm{sys})%$ and we provide a $\ensuremath{\beta}$-neutron energy spectrum.Conclusions: The Modular Total Absorption Spectrometer measurements of $^{137}\mathrm{I}$ and $^{137}\mathrm{Xe}$ demonstrate the importance of revisiting and remeasuring complex $\ensuremath{\beta}$-decaying fission products with total absorption spectroscopy. We demonstrate the ability of the Modular Total Absorption Spectrometer to measure $\ensuremath{\beta}$-delayed neutron energy spectra.

We report the results of a β-decay study of fission products ^{86}Br, ^{89}Kr, ^{89}Rb, ^{90gs}Rb, ^{90m}Rb, ^{90}Kr, ^{92}Rb, ^{139}Xe, and ^{142}Cs performed with the Modular Total Absorption Spectrometer (MTAS) and on-line mass-separated ion beams. These radioactivities were assessed by the Nuclear Energy Agency as having high priority for decay heat analysis during a nuclear fuel cycle. We observe a substantial increase in β feeding to high excited states in all daughter isotopes in comparison to earlier data. This increases the average γ-ray energy emitted by the decay of fission fragments during the first 10 000 s after fission of ^{235}U and ^{239}Pu by approximately 2% and 1%, respectively, improving agreement between results of calculations and direct observations. New MTAS results reduce the reference reactor ν[over ¯]_{e} flux used to analyze reactor ν[over ¯]_{e} interaction with detector matter. The reduction determined by the ab initio method for the four nuclear fuel components, ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu, amounts to 0.976, 0.986, 0.983, and 0.984, respectively.

The $\ensuremath{\beta}$-decay properties of the very neutron-rich nucleus $^{85}\mathrm{Ge}$, produced in the proton-induced fission of $^{238}\mathrm{U}$, were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The level scheme of $\phantom{\rule{0.16em}{0ex}}_{33}^{85}\mathrm{As}_{52}$ populated in $^{85}\mathrm{Ge}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}\ensuremath{\gamma}$ decay was reconstructed and compared to shell-model calculations. The investigation of the systematics of low-energy levels in $N=52$ isotones together with shell-model analysis allowed us to provide an estimate of the low-energy structure of the more exotic $N=52$ isotone $^{81}\mathrm{Cu}$.

A Modular Total Absorption Spectrometer constructed at the Holifield Radioactive Ion Beam Facility has been applied to decay studies of over 20 238 U fission products. The measurements were focused on nuclei identified as important for decay heat analysis during a nuclear fuel cycle. Preliminary results on the average electromagnetic (EM) energy release in the β decay of 89 Kr and 139 Xe isotopes yielded values of 2446 keV and 1126 keV, respectively. It represents an increase of over 35% and 20%, respectively, when compared to the average EM energies deduced using the ENSDF database.

Neutron energy measurements can be achieved using time-of-flight (ToF) techniques. A digital data acquisition system was developed for reliable ToF measurements with subnanosecond timing resolution based on digitizers with 10 ns and 4 ns sampling periods using pulse shape analysis algorithms. A validation procedure was developed to confirm the reliability. The response of the algorithm to photomultiplier signals was studied using a specially designed experimental system based on fast plastic scintillators. The presented developments enabled digital data acquisition systems to instrument the recently developed Versatile Array of Neutron Detectors at Low-Energy (VANDLE).

A highly selective resonant ionization laser ion source has been successfully commissioned at the Holifield Radioactive Ion Beam Facility, Oak Ridge National Laboratory, for the production of pure beams of short-lived nuclei for spectroscopic studies. The laser ion source provided beams of neutron-rich Ga isotopes to the Low-energy Radioactive Ion Beam Spectroscopy Station for beta decay measurements. The radioactive Ga isotopes were produced by 50-MeV proton induced fission of 238 U and ionized by laser radiation using a two-step resonant ionization scheme. Isobarically pure 83 Ga, 85 Ga, and 86 Ga beams were delivered to the experiment at approximate rates of 12,000 ions/s, 100 ions/s, and 3 ions/s, respectively.

$\ensuremath{\beta}$ decay of neutron-rich nuclide $^{94}\mathrm{Kr}$ was reinvestigated by means of a high resolution on-line mass separator and $\ensuremath{\beta}\ensuremath{-}\ensuremath{\gamma}$ spectroscopy. In total 22 $\ensuremath{\gamma}$-ray transitions were assigned to the decay of $^{94}\mathrm{Kr}$, and a new isomeric state was identified. The new information allows us to build detailed levels systematics in a chain of odd-odd rubidium isotopes and draw conclusions on nuclear structure for some of the observed states. The discussed level structure affects the evolution of $\ensuremath{\beta}$-decay half-lives for neutron-rich selenium, krypton, and strontium isotopes.