21 research outputs found
High-precision measurements of low-lying isomeric states in In with JYFLTRAP double Penning trap
Neutron-rich In isotopes have been studied utilizing the double
Penning trap mass spectrometer JYFLTRAP at the IGISOL facility. Using the
phase-imaging ion-cyclotron-resonance technique, the isomeric states were
resolved from ground states and their excitation energies measured with high
precision in In. In In, the states were
separated and their masses were measured while the energy difference between
the unresolved and states, whose presence was confirmed by
post-trap decay spectroscopy was determined to be keV. In addition,
the half-life of Cd, s, was extracted.
Experimental results were compared with energy density functionals, density
functional theory and shell-model calculations.Comment: 11 pages, 7 figure
Nuclear charge radius of Al and its implication for V in the quark-mixing matrix
Collinear laser spectroscopy was performed on the isomer of the aluminium
isotope Al. The measured isotope shift to Al in the
3s^{2}3p\;^{2}\!P^\circ_{3/2} \rightarrow 3s^{2}4s\;^{2}\!S_{1/2} atomic
transition enabled the first experimental determination of the nuclear charge
radius of Al, resulting in =\qty{3.130\pm.015}{\femto\meter}. This
differs by 4.5 standard deviations from the extrapolated value used to
calculate the isospin-symmetry breaking corrections in the superallowed
decay of Al. Its corrected value, important for the
estimation of in the CKM matrix, is thus shifted by one standard
deviation to \qty{3071.4\pm1.0}{\second}.Comment: 5 pages, 2 figures, submitted to Phys. Rev. Let
Penning-trap mass measurement of Hf
International audienceWe report on the precise mass measurement of the Hf isotope performed at the Ion Guide Isotope Separator On-Line facility using the JYFLTRAP double Penning trap mass spectrometer. The new mass-excess value, ~keV, is in agreement with the literature while being nine times more precise. The newly determined Hf electron-capture value, ~keV, allows us to firmly reject the population of an excited state at 1578 keV in Lu and 11 transitions tentatively assigned to the decay of Hf. Our refined mass value of Hf reduces mass-related uncertainties in the reaction rate of HfHf. Thus, the rate for the main photodisintegration destruction channel of the nuclide Hf in the relevant temperature region for the process is better constrained
VADER: A novel decay station for actinide spectroscopy
A research programme focused on the study of the nuclear structure of actinide isotopes has recently been
implemented at the IGISOL facility, University of JyvÀskylÀ. Within this scope, a new decay station named
VADER (Versatile Actinides DEcay spectRoscopy setup) has been developed and commissioned. The system
consists of a compact array of silicon detectors, a liquid-nitrogen-cooled silicon lithium (Si(Li)) detector and
three broad energy germanium detectors (BEGe), placed around a thin implantation carbon foil. The combined
use of different detectors allows the measurement of particles, conversion electrons and de-excitation rays in coincidence, enabling a full reconstruction of nuclear decay schemes. The measurement of basic nuclear decay observables provides a picture of the nuclear shell evolution in neutron-deficient actinides, and highlights the possible emergence of reflection-asymmetric shapes in the region.nonPeerReviewe
decay -value measurement of Cs and its implications to neutrino studies
International audienceThe decay -value of Cs (, ~days) was measured with the JYFLTRAP Penning trap setup at the Ion Guide Isotope Separator On-Line (IGISOL) facility of the University of JyvÀskylÀ, Finland. The mono-isotopic samples required in the measurements were prepared with a new scheme utilised for the cleaning, based on the coupling of dipolar excitation with Ramsey's method of time-separated oscillatory fields and the phase-imaging ion-cyclotron-resonance (PI-ICR) technique. The value is determined to be 2536.83(45) keV, which is 4 times more precise and 11.4(20) keV ( 6) smaller than the adopted value in the most recent Atomic Mass Evaluation AME2020. The daughter, Ba, has a 4 state at 2544.481(24) keV and a state at 2532.653(23) keV, both of which can potentially be ultralow -value end-states for the Cs decay. With our new ground-to-ground state value, the decay energies to these two states become -7.65(45) keV and 4.18(45) keV, respectively. The former is confirmed to be negative at the level of 17, which verifies that this transition is not a suitable candidate for neutrino mass determination. On the other hand, the slightly negative value makes this transition an interesting candidate for the study of virtual - transitions. The decay to the 3 state is validated to have a positive low value which makes it a viable candidate for neutrino mass determination. For this transition, we obtained a shell-model-based half-life estimate of yr
Mass measurements in the Sn region with the JYFLTRAP double Penning trap mass spectrometer
International audienceWe report on new precision mass measurements of neutron-rich Sb and I isotopes from the JYFLTRAP double Penning trap mass spectrometer. We confirm the value from the previous Penning-trap measurement of Sb at the Canadian Penning Trap and therefore rule out the conflicting result from the Experimental Storage Ring. The ground state and isomer in I were resolved and measured directly for the first time. The isomer excitation energy, keV, agrees with the literature but is three times more precise. The measurements have improved the precision of the mass values and confirmed previous results in the majority of cases. However, for I the results differ by 17(6) keV and 23(12) keV, respectively. This could be explained by an unresolved contamination or different ratio of unresolved isomeric states in the case of I
First trap-assisted decay spectroscopy of the Ge ground state
The -delayed spectroscopy of As has been performed using a purified beam of Ge ground state at the Ion Guide Isotope Separator On-Line facility (IGISOL). The Ge ions were produced using proton-induced fission of Th and selected with the double Penning trap JYFLTRAP for the post-trap decay spectroscopy measurements. The low-spin isomeric-state ions were not observed in the fission products. The intrinsic half-life of the Ge ground state has been determined as , which is significantly shorter than the literature value. A new level scheme of As has been built and is compared to shell-model calculations