Search results for "beta-decay"

The $\beta$-delayed one- and two-proton emission of $^{27}$S

2001

In an experiment performed at the GANIL LISE3 facility, radioactive 27S isotopes have been produced by projectile fragmentation of a 95 AMeV 36Ar primary beam. After selection by means of the LISE3 separator, the isotope of interest was implanted in a silicon-detector telescope where its half-life ( T 1/2 = 15.5(15) ms) and its main decay branches were measured.

Electron spectra in forbidden β decays and the quenching of the weak axial-vector coupling constant gA

2017

Evolution of the electron spectra with the effective value of the weak axial-vector coupling constant ${g}_{\mathrm{A}}$ was followed for 26 first-, second-, third-, fourth- and fifth-forbidden ${\ensuremath{\beta}}^{\ensuremath{-}}$ decays of odd-$A$ nuclei by calculating the involved nuclear matrix elements (NMEs) in the framework of the microscopic quasiparticle-phonon model (MQPM). The next-to-leading-order terms were included in the $\ensuremath{\beta}$-decay shape factor of the electron spectra. The spectrum shapes of third- and fourth-forbidden nonunique decays were found to depend strongly on the value of ${g}_{\mathrm{A}}$, while first- and second-forbidden decays were mostly unaff…

Total absorption γ-ray spectroscopy of beta delayed neutron emitters

2013

Preliminary results of the data analysis of the beta decay of 94Rb using a novel - segmented- total absorption spectrometer are shown in this contribution. This result is part of a systematic study of important contributors to the decay heat problem in nuclear reactors. In this particular case the goal is to determine the beta intensity distribution below the neutron separation energy and the gamma/beta competition above.

Structure And Decay Of Neutron-Rich Nuclides In The 115 ≤ A ≤ 138 Mass Range And r-Process Nucleosynthesis

2005

The structure and decay of neutron‐rich r‐process nuclides has been studied by a variety of means that take advantage of enhanced selectivity to permit identification of exotic nuclides. New level structures are presented for 134,135Sb along with data for Ag isomers and Cd yrast structures. Some of the properties measured play an important role in calculations of the yields of elements and isotopes produced in r‐process nucleosynthesis that takes place at high temperature in the presence of large densities of neutrons.

Light exotic isotopes: recent beam developments and physics applications at ISOLDE

2002

This paper is divided in three parts: (i) the measurement of yields and decay losses of Li and Be isotopes released from a thin foil tantalum target at the CERN/ISOLDE PS-Booster; (ii) results from beta-decay experiments on Be-12 and Be-14, an improved half-life of 21.49(3) ms has been obtained for Be-12; (iii) the beta-decay of C-9. An outline of the analysis procedure to determine the branching at high excitation energies is given. The ground-state branch has been determined to 54.1(15)%.

Revised rates for the stellar triple-alpha process from measurement of C-12 nuclear resonances

2005

4 pages, 3 figures.-- PMID: 15650733 [PubMed].

Single and Double Beta-Decay Q Values among the Triplet 96Zr, 96Nb, and 96Mo

2015

The atomic mass relations among the mass triplet ^{96}Zr, ^{96}Nb, and ^{96}Mo have been determined by means of high-precision mass measurements using the JYFLTRAP mass spectrometer at the IGISOL facility of the University of Jyväskylä. We report Q values for the ^{96}Zr single and double β decays to ^{96}Nb and ^{96}Mo, as well as the Q value for the ^{96}Nb single β decay to ^{96}Mo, which are Q_{β}(^{96}Zr)=163.96(13), Q_{ββ}(^{96}Zr)=3356.097(86), and Q_{β}(^{96}Nb)=3192.05(16)  keV. Of special importance is the ^{96}Zr single β-decay Q value, which has never been determined directly. The single β decay, whose main branch is fourfold unique forbidden, is an alternative decay path to the…

Decay properties of 114Ag

1971

Electron spectra in forbidden β decays and the quenching of the weak axial-vector coupling constant gA

2017

Evolution of the electron spectra with the effective value of the weak axial-vector coupling constant gA was followed for 26 first-, second-, third-, fourth- and fifth-forbidden β− decays of odd-A nuclei by calculating the involved nuclear matrix elements (NMEs) in the framework of the microscopic quasiparticle-phonon model (MQPM). The next-to-leading-order terms were included in the β-decay shape factor of the electron spectra. The spectrum shapes of third- and fourth-forbidden nonunique decays were found to depend strongly on the value of gA, while first- and second-forbidden decays were mostly unaffected by the tuning of gA. The gA-driven evolution of the normalized β spectra was found t…

Studies of Weak Beta-Delayed Protons Emitted in the Decay of Odd-Z, Tz = -3/2 Nuclei

1983

Radioactive decay of Tz = - 3/2 nuclides, 27P and 31Cl, predicted to be weak β-delayed proton precursors, have been looked for. Two proton groups having energies of 989 ± 15 and 1528 ± 20 keV and a half-life of 150 ± 25 ms were associated with the decay of 31Cl. The search for 27P is still under way, but the first qualitative results are briefly discussed.