Search results for "Decay"
showing 10 items of 2087 documents
Isovector spin-multipole strength distributions in double- β -decay triplets
2017
In this work the energetics and strength distributions of isovector spin-dipole and spin-quadrupole transitions from the ground states of the pairs ($^{76}\mathrm{Ge}, ^{76}\mathrm{Se}$), ($^{82}\mathrm{Se}, ^{82}\mathrm{Kr}$), ($^{96}\mathrm{Zr}, ^{96}\mathrm{Mo}$), ($^{100}\mathrm{Mo}, ^{100}\mathrm{Ru}$), ($^{116}\mathrm{Cd}, ^{116}\mathrm{Sn}$), ($^{128}\mathrm{Te}, ^{128}\mathrm{Xe}$), ($^{130}\mathrm{Te}, ^{130}\mathrm{Xe}$), and ($^{136}\mathrm{Xe}, ^{136}\mathrm{Ba}$), of double-$\ensuremath{\beta}$-decay initial and final nuclei, to the ${J}^{\ensuremath{\pi}}={0}^{\ensuremath{-}},{1}^{\ensuremath{-}},{2}^{\ensuremath{-}},{1}^{+},{2}^{+}$, and ${3}^{+}$ excited states of the interm…
Determination of β -decay ground state feeding of nuclei of importance for reactor applications
2020
12 pags., 6 figs., 3 tabs.
Total Absorption Spectroscopy of Fission Fragments Relevant for Reactor Antineutrino Spectra Determination
2015
8 pags., 3 figs., 1 tab. ; Presented at the XXXIV Mazurian Lakes Conference on Physics, Piaski, Poland, September 6–13, 2015.
Level structure of 99Nb
1998
The β decay of 97Sr to 97Y has been investigated using ion-guide on-line mass separation and a 10 Ge-detector array to record γ−γ coincidences to a detection limit well below that of former studies. Similarities are found in the β-decay patterns of 99Zr and of its isotone 97Sr and also in the γ-ray decay rates and branchings of the corresponding levels in their respective daughters 99Nb and 97Y. This indicates a persisting influence of the d5/2 neutron shell closure for 99Nb. The level structure of 99Nb and the β-feeding pattern are discussed in the frame of the interacting boson-fermion plus broken pair model and the microscopic quasiparticle phonon model.
Towards Laser Spectroscopy of Superheavy Elements
2016
The sensitivity of laser spectroscopic methods has been increased over the past two decades dramatically so that today the spectroscopy of superheavy elements appears on the horizon as a realistic option. For elements with Z > 100 no experimental atomic or ionic level structure information is known so far. These elements cannot be bread in high flux nuclear power reactors via successive neutron capture and \(\beta ^-\) decay but must be produced in accelerator-based nuclear fusion-evaporation reactions. Laser spectroscopic investigations at low rates take advantage of the storage of ions or atoms in rare gas traps. A first successful experiment was conducted only recently for the element no…
Searches for neutrinoless resonant double electron captures at LNGS
2012
Several experiments were performed during last years at underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (LNGS) of the INFN (Italy) to search for resonant 2$\varepsilon0\nu$ captures in 96Ru, 106Cd, 136Ce, 156Dy, 158Dy, 180W, 184Os, 190Pt with the help of HP Ge semiconductor detectors, and ZnWO4 and 106CdWO4 crystal scintillators. No evidence for r-2$\varepsilon0\nu$ decays was found, and only T_{1/2} limits were established in the range of 10^{14}-10^{21} yr.
Alpha-Photon Coincidence Spectroscopy Along Element 115 Decay Chains
2014
Produced in the reaction 48Ca+243Am, thirty correlated α-decay chains were observed in an experiment conducted at the GSI Helmholzzentrum fur Schwerionenforschung, Darmstadt, Germany. The decay chains are basically consistent with previous findings and are considered to originate from isotopes of element 115 with mass numbers 287, 288, and 289. A set-up aiming specifically for high-resolution charged particle and photon coincidence spectroscopy was placed behind the gas-filled separator TASCA. For the first time, γ rays as well as X-ray candidates were observed in prompt coincidence with the α-decay chains of element 115.
ISOLTRAP Mass Measurements for Weak-Interaction Studies
2005
International audience; The conserved-vector-current (CVC) hypothesis of the weak interaction and the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix are two fundamental postulates of the Standard Model. While existing data on CVC supports vector current conservation, the unitarity test of the CKM matrix currently fails by more than two standard deviations. High-precision mass measurements performed with the ISOLTRAP experiment at ISOLDE/CERN provide crucial input for these fundamental studies by greatly improving our knowledge of the decay energy of super-allowed beta decays. Recent results of mass measurements on the beta emitters 18Ne, 22Mg, 34Ar, and 74Rb as pertaining to weak-i…
Study of Intermediate-spin States of $^{98}$Y
2015
The nuclear structure of the odd–odd nucleus 98Y has been re-investigated by observing prompt γ rays emitted following the proton-induced fission of a 238U target, using the JUROGAM-II multidetector array. New highspin decays have been observed and placed in the level schemes using triple coincidences. The experimental level energies and γ-decay patterns are compared to GICM and QPRM calculations, assuming that this neutronrich N = 59 isotone is spherical at low energies and prolate deformed at intermediate spins. Web of Science 47 3 916 911
High-frequency Ramsey excitation in a Penning trap
2007
The Ramsey excitation method for high-precision mass-measurements of highly-charged ions has been investigated and benchmarked using H2+ ions in the Penning-trap mass-spectrometer SMILETRAP. The reason for using H2+ ions are their high cyclotron frequency which is typical for the highly-charged ions usually used at SMILETRAP. Two-, three- and four-pulse Ramsey excitation data are analyzed with the help of recent theoretical work and are compared with the previously used single-pulse excitation data. An improvement factor of 2.9 in the statistical uncertainty is achieved. Furthermore the mass of 76Se, included in the previous Q-value measurement of the 76Ge neutrinoless double beta decay, is…