Search results for "beta decay"
showing 10 items of 501 documents
Gamow-Teller Beta Decay of Neutron Rich Tc, Ru, Rh and Pd Isotopes
1988
During recent experiments at the IGISOL-facility several new neutron rich nuclides have been discovered, including the first direct observations of the beta decays of 111Tc, 112Ru, 113Ru, 114Ru, 113Rh, 115Rh, 116Rh and 118Pd. The role of the νg7/2 → πg9/2 transformation in the beta decays of the odd-odd 110–116Rh and the even-even 114–118Pd isotopes is shown to be dominant. The experimental results are compared with shell model calculations including deformation and pairing.
Double-βtransformations in isobaric triplets with mass numbersA=124, 130, and 136
2012
The Q values of double-electron capture in ${}^{124}$Xe, ${}^{130}$Ba, and ${}^{136}$Ce and double-beta decay of ${}^{124}$Sn and ${}^{130}$Te have been determined with the Penning-trap mass spectrometer SHIPTRAP with a few hundred eV uncertainty. These nuclides are members of three isobaric triplets with common daughter nuclides. The main goal of this work was to investigate the existence of the resonant enhancement of the neutrinoless double-electron-capture rates in ${}^{124}$Xe and ${}^{130}$Ba in order to assess their suitability for the search for neutrinoless double-electron capture. Based on our results, in neither of these cases is the resonance condition fulfilled.
Branching ratios in theβdecays ofN12andB12
2009
Absolute branching ratios to unbound states in C-12 populated in the beta decays of N-12 and B-12 are reported. Clean sources of N-12 and B-12 were obtained using the isotope separation on-line (ISOL) method. The relative branching ratios to the different populated states were extracted using single-alpha as well as complete kinematics triple-alpha spectra. These two largely independent methods give consistent results. Absolute normalization is achieved via the precisely known absolute branching ratio to the bound 4.44 MeV state in C-12. The extracted branching ratios to the unbound states are a factor of three more precise than previous measurements. Branching ratios in the decay of Na-20 …
Subshell closure effects on the collectivity of 36 88 Kr52 and the beta decay of88Br to levels in88Kr
1986
The level structure of88Kr has been investigated by measurements on chemically separated bromine samples. A total of 146γ-rays have been assigned to the decay of88Br, and a level scheme with 58 levels is proposed. The collectivity of88Kr has been investigated within the framework of the Interacting Boson Approximation (IBA-2 model). Comparison of our detailedγ-ray data and calculations have led to the establishment of a protonhole boson desciption rather than protonparticle nature. This supports recent works establishingZ=40 as a major subshell closure.
In-beam and decay spectroscopy of transfermium nuclei
2008
Abstract In recent years the body of experimental data on nuclei with masses A ≃ 250 has increased dramatically. Nuclei that had been out of reach for experimental studies have now become available for study through a variety of approaches, both with in-beam spectroscopic methods and through spectroscopy following the decay of isomeric states or alpha decays at the focal plane of powerful separators. This article aims to collect the currently available experimental data on nuclei between Cm ( Z = 96 ) and Db ( Z = 105 ) . The review of this data builds on the evaluations in the literature and focusses on those datasets obtained most recently.
β-decay ofO13
2005
The beta decay of O-13 has been studied at the IGISOL facility of the Jyvaskyla accelerator centre (Finland). By developing a low-energy isotope-separated beam of O-13 and using a modern segmented charged-particle detector array an improved measurement of the delayed proton spectrum was possible. Protons with energy up to more than 12 MeV are measured and the corresponding log(ft) values extracted. A revised decay scheme is constructed. The connection to molecular states and the shell model is discussed.
Note on the decay of200Au
1972
Gamma and beta rays from the decay of200Au (48.4 min) were studied employing Ge(Li) and plastic detectors in various singles and coincidence arrangements. The intensity of the β-branch to the ground state of200Hg was determined as 79%, and the disintegration energy of200Au to be asQβ=2.26 ± 0.06 MeV. A tentative spin and parity assignment of (1,2)+ is proposed for levels at 1515.2 and 1972.5 keV in 200Hg
R-matrix analysis of theβdecays ofN12andB12
2010
The β decays of 12N and 12B have been studied at KVI and JYFL to resolve the composition of the broad and interfering 0+ and 2+ strengths in the triple-α continuum. For the first time a complete treatment of 3α decay is presented including all major breakup channels. A multilevel, many-channel R-matrix formalism has been developed for the complete description of the breakup in combination with the recently published separate analysis of angular correlations. We find that, in addition to the Hoyle state at 7.65 MeV, more than one 0+ and 2+ state is needed to reproduce the spectra. Broad 03+ and 22+ states are found between 10.5 and 12 MeV in this work. The presence of β strength up to the 12…
Beta decay energies and nuclear masses of148Ba,148La and151Pr
1990
Theβ-decay energy of the neutron-rich isotopes148Ba,148La and151Pr has been measured at the Institute Laue-Langevin (ILL). The148Ba- and148La-nuclei were produced using a high-temperature ion source at the OSTIS separator of this institute, whereas samples of151Pr were obtained from the thermal fission of239Pu, used as a target in the mass separator LOHENGRIN. At both instruments,βγ-coincidences were measured with a plastic scintillator telescope and a Ge(I)-detector, together withβ-singles andγ-singles spectra. Theβ-spectra emitted in coincidence with 44γ-lines in the decay of these nuclei have been evaluated. From their endpoint energies, the followingQβ-values have been obtained:Qβ(148Ba…
Determination of the spin of 31Ar
1999
Abstract The beta-delayed proton emission from the lightest Ar-isotopes has been recorded with a high-granularity, large solid-angle Si-detector set-up. Proton energy shifts due to beta-recoil have been measured. We demonstrate how this allows the spin of 31 Ar to be determined as 5/2. The method can be applied at decay rates as low as 1 s −1 .