Search results for "Cadmi"
showing 10 items of 442 documents
Forbidden nonuniqueβdecays and effective values of weak coupling constants
2016
Forbidden nonunique $\ensuremath{\beta}$ decays feature shape functions that are complicated combinations of different nuclear matrix elements and phase-space factors. Furthermore, they depend in a very nontrivial way on the values of the weak coupling constants, ${g}_{\mathrm{V}}$ for the vector part and ${g}_{\mathrm{A}}$ for the axial-vector part. In this work we include also the usually omitted second-order terms in the shape functions to see their effect on the computed decay half-lives and electron spectra ($\ensuremath{\beta}$ spectra). As examples we study the fourth-forbidden nonunique ground-state-to-ground-state ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay branches of $^{113}\ma…
Selective laser ionization of very neutron-rich cadmium isotopes: Decay properties of131Cd83and132Cd84
2000
A chemically selective laser ion source has been applied in a decay study of the very neutron-rich isotopes ${}^{131}\mathrm{Cd}$ and ${}^{132}\mathrm{Cd}$ at CERN/ISOLDE. For the ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay of the $N=83$ nuclide ${}^{131}\mathrm{Cd}$ a surprisingly short half-life of $(68\ifmmode\pm\else\textpm\fi{}3)$ ms and a weak delayed-neutron branch of ${P}_{n}=(3.5\ifmmode\pm\else\textpm\fi{}1.0)%$ were observed. For the $N=84$ nuclide ${}^{132}\mathrm{Cd}$ a half-life of $(97\ifmmode\pm\else\textpm\fi{}10)$ ms and a ${P}_{n}$ value of $(60\ifmmode\pm\else\textpm\fi{}15)%$ were obtained. Schematic features of both decay schemes are developed. We find that our new d…
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.
Time-dependent electric field in Al/CdTe/Pt detectors
2015
Abstract Al/CdTe/Pt detectors are very attractive devices for high-resolution X-ray spectroscopy, even though they suffer from bias-induced time instability (polarization). Polarization phenomena cause a progressive time-degradation of the spectroscopic performance of the detectors, due to hole trapping and detrapping from deep acceptor levels that directly control the electric field distribution. In this work we present experimental investigations on the electric field profile of planar Al/CdTe/Pt detectors by means of Pockels effect measurements. The time/temperature dependence of the electric field was investigated in a long time window (up to 10 h) and the correlation with the reverse c…
Polarization phenomena in Al/p-CdTe/Pt X-ray detectors
2013
Over the last decades, CdTe detectors are widely used for the development of room temperature X-ray and gamma ray spectrometers. Typically, high resolution CdTe detectors are fabricated with blocking contacts (indium, aluminum) ensuring low leakage currents and high electric field for optimum charge collection. As well known, time instability under bias voltage (termed as polarization) is the major drawback of CdTe diode detectors. Polarization phenomena cause a progressive degradation of the spectroscopic performance with time, due to hole trapping and detrapping from deep acceptors levels. In this work, we studied the polarization phenomenon on new Al/p-CdTe/Pt detectors, manufactured by …
A CdTe position sensitive spectrometer for hard X- and soft γ-ray polarimetry
2002
Coded Imager and Polarimeter for High Energy Radiation (CIPHER) is a hard X- and soft gamma- ray spectroscopic and polarimetric coded mask telescope based on an array of Cadmium telluride microspectrometers. The position sensitive detector (PSD) will be arranged in 4 modules of 32 x 32 crystals, each of 2 x 2 mm(2) cross-section and 10 mm thickness giving a total active area of about 160 cm(2), operating over a wide energy range (similar to10 keV to 1 MeV). Each PSD module is obtained by aligning 32 linear arrays of micro-detectors each also containing the integrated analog front end electronics on a thin ceramic layer. The CIPHER instrument will be proposed for a balloon experiment, both i…
Neutrino scattering off the stable cadmium isotopes: neutral-current processes
2014
In this work we present computed cross sections for the incoherent neutral-current neutrino scattering off the stable cadmium isotopes. The main focus is on supernova neutrinos. The nuclear states of the even-mass and odd-mass cadmium isotopes have been constructed using the quasiparticle random-phase approximation and the microscopic quasiparticle-phonon model, respectively. The computed cross sections are folded with suitably parametrized Fermi–Dirac distributions of the supernova (anti)neutrinos energies to obtain realistic estimates of the nuclear responses to these neutrinos.
Approaching theN=82shell closure with mass measurements of Ag and Cd isotopes
2010
Mass measurements of neutron-rich Cd and Ag isotopes were performed with the Penning trap mass spectrometer ISOLTRAP. The masses of ${}^{112,114\ensuremath{-}124}$Ag and ${}^{114,120,122\ensuremath{-}124,126,128}$Cd, determined with relative uncertainties between $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ and $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$, resulted in significant corrections and improvements of the mass surface. In particular, the mass of $^{124}\mathrm{Ag}$ was previously unknown. In addition, other masses that had to be inferred from $Q$ values of nuclear decays and reactions have now been measured directly. The analysis includes various mass…
Production of very neutron-deficient isotopes near Sn via reactions involving light-particle and cluster emission
2000
Abstract The production of very neutron-deficient isotopes near 100Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete-fusion reactions. We measured the cross sections for 99Cd, 100In, 101Sn and 102In via 58Ni+58Ni fusion reactions followed by cluster emission, and via 58Ni+50Cr fusion reactions accompanied by evaporation of protons, neutrons or α particles. Both types of reactions yield similar cross sections for the production of exotic nuclei near 100Sn. The data are discussed in comparison with results obtained from statistical-model calculations.
Medium-spin structure of neutron-rich Pd and Cd isotopes
2003
Cadmium isotopes are traditionally considered as good examples of nearly spherical, vibrational nuclei, which can be described by quadrupole vibrators in the collective model, as well as the U(5) dynamical symmetry in the interacting boson model (IBM). However, the shape coexistence of more deformed intruder states originating from proton 2p–4h excitation across the Z = 50 major shell is another interesting structural aspect, whose presence in Pd-isotopes has also been demonstrated [1,2].