Search results for "isotopes of palladium"
showing 10 items of 13 documents
Microscopic anharmonic vibrator approach for beta decays
2007
Abstract We formulate a microscopic description of charge-changing excitations, including dynamical mixture of one- and two-phonon states. The present formalism generalizes our previous microscopic anharmonic vibrator approach (MAVA), designed to treat charge-conserving two- and four-quasiparticle degrees of freedom and their mixing. In the present formalism, the proton–neutron MAVA, pnMAVA, the main building blocks are the quasiparticle random-phase approximation (QRPA) phonons in the charge-conserving channels, and the proton–neutron QRPA (pnQRPA) phonons in the charge-changing channels. The QRPA and pnQRPA equations are directly used in deriving the equations of motion for two-phonon sta…
Collinear laser spectroscopy of stable palladium isotopes at the IGISOL facility
2020
AbstractCollinear laser spectroscopy on stable palladium isotopes was performed at the IGISOL facility in Jyväskylä in preparation for an experiment on its neutron-rich isotopes. Five transitions from different initial atomic states were tested, with the goal of finding the most spectroscopically efficient. The observed intensities afforded a comparison with atomic-level population predictions based on charge-exchange calculations. For some transitions hyperfine parameters of 105Pd were measured, which were found to be in good agreement with literature values. A King plot analysis was performed using the measured isotope shifts and known charge radii from literature to determine the atomic …
Direct mass measurements of cadmium and palladium isotopes and their double-βtransitionQvalues
2012
The Q-value of the double-electron capture in Cd-108 has been determined to be (272.04 +/- 0.55) keV in a direct measurement with the double-Penning trap mass spectrometer TRIGA-TRAP. Based on this result a resonant enhancement of the decay rate of Cd-108 is excluded. We have confirmed the double-beta transition Q-values of Cd-106 and Pd-110 recently measured with the Penning-trap mass spectrometers SHIPTRAP and ISOLTRAP, respectively. Furthermore, the atomic masses of the involved nuclides Cd-106, Cd-108, Cd-110, Pd-106, Pd-108 and Pd-110 have been directly linked to the atomic mass standard.
Collective 2$^{+1}$ excitations in$^{206}$Po and$^{208,210}$Rn
2016
In the present study, $B(E2; 2^{+}_{1}\rightarrow 0^{+}_{1})$ values have been measured in the 208,210Rn and 206Po nuclei through Coulomb excitation of re-accelerated radioactive beams in inverse kinematics at CERN-ISOLDE. These nuclei have been proposed to lie in, or at the boundary of the region where the seniority scheme should persist. However, contributions from collective excitations are likely to be present when moving away from the N=126 closed shell. Such an effect is confirmed by the observed increased collectivity of the $2^{+}_{1}\rightarrow 0^{+}_{1}$ transitions. Experimental results have been interpreted with the aid of theoretical studies carried out within the BCS-based QRP…
Neutron configurations in 113Pd
2014
Excited states in 113Pd, populated in β− decay of 113Rh and in spontaneous fission of 248Cm and 252Cf, have been studied by means of γ spectroscopy at the IGISOL facility of Jyvaskylä University and using large arrays of Ge detectors (Eurogam2 and Gammasphere, respectively). The position of the 11/2− yrast excitation in 113Pd, proposed recently at 166.1 keV by other authors, has been corrected to 98.9 keV. The decay of this level has been discussed to explain the observed transition intensities. The 7/2− member of the yrast, unique-parity configuration has been identified at 84.9 keV and a band on top of this level proposed. On top of the 1/2+, first excited state a band has been built and …
Isomers inPd128andPd126: Evidence for a Robust Shell Closure at the Neutron Magic Number 82 in Exotic Palladium Isotopes
2013
The level structures of the very neutron-rich nuclei $^{128}\mathrm{Pd}$ and $^{126}\mathrm{Pd}$ have been investigated for the first time. In the $r$-process waiting-point nucleus $^{128}\mathrm{Pd}$, a new isomer with a half-life of $5.8(8)\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ is proposed to have a spin and parity of ${8}^{+}$ and is associated with a maximally aligned configuration arising from the ${g}_{9/2}$ proton subshell with seniority $\ensuremath{\upsilon}=2$. For $^{126}\mathrm{Pd}$, two new isomers have been identified with half-lives of 0.33(4) and $0.44(3)\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$. The yrast ${2}^{+}$ energy is much higher in $^{128}\mathrm{Pd}$ than in…
Plunger Lifetime Measurements in 102Pd
2006
Recently, an intense experimental effort has been devoted to the search of empirical proofs of critical‐point symmetries in nuclear structure. These symmetries describe shape‐phase transitions and provide parameter‐free predictions (up to over‐all scale factors) for excitation spectra and B(E2) values. This contribution reports on recent plunger‐lifetime measurements ON 102Pd carried out at LNL, Legnaro, with the Cologne plunger apparatus coupled to the GASP spectrometer and using the 92Zr(13C,3n)102Pd reaction at 48 MeV. According to the results of our measurements, 102Pd is so far the best known paradigm of the E(5) critical‐point symmetry.
Decay spectroscopy of neutron-rich nuclei with A $$ \simeq $$ 100
2012
We review structure data obtained by decay spectroscopy of neutron-rich nuclei of mass close to 100. Emphasis is put on the contribution of experiments at IGISOL in the nineties. They confirmed the earlier postulated shape coexistence in the fast shape-transition region between N = 58 (spherical ground states and low collectivity) and N = 60 (strong axial deformation). A detailed spectroscopic study of the A = 99 chain established the upper-Z limit of the N = 56 shell closure region with 99Nb, owing to striking similarities with 97Y. A consequence of the N = 56 closure is that the s 1/2 odd-neutron becomes the ground state of the most neutron-rich N = 57 isotones, starting with 99Mo, instea…
Excited states inPd115populated in theβ−decay ofRh115
2010
Excited states in $^{115}\mathrm{Pd}$, populated following the ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay of $^{115}\mathrm{Rh}$ have been studied by means of $\ensuremath{\gamma}$ spectroscopy after the Penning-trap station at the IGISOL facility, University of Jyv\"askyl\"a. The $1$$/$$2$${}^{+}$ spin and parity assignment of the ground state of $^{115}\mathrm{Pd}$, confirmed in this work, may indicate a transition to an oblate shape in Pd isotopes at high neutron number.
Beta Decay of68–74Niand Level Structure of Neutron-Rich Cu Isotopes
1998
The isotopes ${}^{68--74}\mathrm{Ni}$, of interest both for nuclear physics and astrophysics, have been produced in proton-induced fission of ${}^{238}\mathrm{U}$ and ionized in a laser ion guide coupled to an on-line mass separator. Their $\ensuremath{\beta}$ decay was studied by means of $\ensuremath{\beta}$- $\ensuremath{\gamma}$ and $\ensuremath{\gamma}$- $\ensuremath{\gamma}$ spectroscopy. Half-lives have been determined and production cross sections extracted. A partial level scheme is presented for ${}^{73}\mathrm{Cu}$ and additional levels for ${}^{71}\mathrm{Cu}$, providing evidence for a sharply lowered position of the $\ensuremath{\pi}{1f}_{5/2}$ orbital as occupancy of the $\ens…