Search results for "Nuclide"
showing 10 items of 397 documents
In-beam study of high-spin states in199,200,201Po and systematical features of Z=84 polonium isotopes
1985
Excited states in199,200,201Po were populated in the reactions12C+194Pt and12C+195Pt. The subsequentγ-radiation was studied using conventional in-beam spectroscopic methods. States with spins up to (29/2), 18 and ≧35/2ħ, respectively, were populated in the three nuclides. Three isomeric states with the following half-lives were observed in200Po:T1/2(8+)=90(15) ns,T1/2(11−)=120(20) ns andT1/2(12+)=267(4) ns. The structure of the excited states was interpreted within the framework of the spherical shell model. The three isomers are suggested to be two-quasiparticle states with configurationsπ(h22)8J, π(h9i13/2)11- and v(i1 3/2−2)12+. A self-consistent Hartree-Fock calculation was performed to…
Targets on superhydrophobic surfaces for laser ablation ion sources
2012
Target preparation techniques for a laser ablation ion source at the Penning-trap mass spectrometer TRIGA-TRAP have been investigated with regard to future experiments with actinides. To be able to perform mass measurements on these nuclides considering their limited availability, an efficient target preparation technique is mandatory. Here, we report on a new approach for target production using backings, which are pretreated in a way that a superhydrophobic surface is formed. This resulted in improved targets with a more homogeneous distribution of the target material compared to standard techniques with unmodified backings. It was demonstrated that the use of these new targets in a laser…
TRIGA-SPEC: A setup for mass spectrometry and laser spectroscopy at the research reactor TRIGA Mainz
2008
The research reactor TRIGA Mainz is an ideal facility to provide neutron-rich nuclides with production rates sufficiently large for mass spectrometric and laser spectroscopic studies. Within the TRIGA-SPEC project, a Penning trap as well as a beam line for collinear laser spectroscopy are being installed. Several new developments will ensure high sensitivity of the trap setup enabling mass measurements even on a single ion. Besides neutron-rich fission products produced in the reactor, also heavy nuclides such as 235-U or 252-Cf can be investigated for the first time with an off-line ion source. The data provided by the mass measurements will be of interest for astrophysical calculations on…
Electron capture on116In and implications for nuclear structure related to double-βdecay
2013
The electron capture decay branch of ${}^{116}$In has been measured to be $[2.46\ifmmode\pm\else\textpm\fi{}0.44(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.39(\mathrm{syst}.)]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ using Penning trap-assisted decay spectroscopy. The corresponding Gamow-Teller transition strength is shown to be compatible with the most recent value extracted from the $(p,n)$ charge-exchange reaction, providing a resolution to longstanding discrepancies. This transition can now be used as a reliable benchmark for nuclear-structure calculations of the matrix element for the neutrinoless double-$\ensuremath{\beta}$ decay of ${}^{116}$Cd and other nuclides.
First observation of gamma-rays from the proton emitter 171Au
2003
Gamma-rays from the alpha- and proton-unstable nuclide 171Au have been observed for the first time. The gamma-rays were correlated with both a proton- and an alpha-particle decay branch, confirming that the nucleus decays by alpha and proton emission from a single (11/2-) state. The measurement confirms the previously determined half-lives for these particle decays but the present values are of higher precision. In addition, a longer half-life than determined in previous work was measured for the proton-unstable tentative ground state. The results are discussed in relation to structures in neighbouring nuclei and compared with a Strutinsky-type TRS calculation.
Direct mass measurements of the heaviest elements with Penning traps
2013
Abstract Penning-trap mass spectrometry (PTMS) is a mature technique to provide atomic masses with highest precision. Applied to radionuclides it enables us to investigate their nuclear structure via binding energies and derived quantities such as nucleon separation energies. Recent progress in slowing down radioactive ion beams in buffer gas cells in combination with advanced ion-manipulation techniques has opened the door to access even the elements above fermium by PTMS. Such elements are produced in complete fusion–evaporation reactions of heavy ions with lead, bismuth, and actinide targets at very low rates. Pioneering high-precision mass measurements of nobelium and lawrencium isotope…
Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE
2017
At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of–the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210–950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, …
ISOLTRAP mass measurements of exotic nuclides at
2005
The ISOLTRAP experiment at the ISOLDE facility at CERN is a Penning trap mass spectrometer for on-line mass measurements on short-lived radionuclides. It allows the determination of atomic masses of exotic nuclides with a relative uncertainty of only 10−8. The results provide important information for, e.g., weak interaction studies and nuclear models. Recent ISOLTRAP investigations and applications of high-precision mass measurements are discussed.
Isoltrap pins down masses of exotic nuclides
2005
The mass of radionuclides contribute to a variety of fundamental studies including tests of the weak interaction and the Standard Model. The limits of mass measurements of exotic nuclides have been extended considerably by the Penning-trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN. Recent ISOLTRAP measurements are summarized and current technical improvements are outlined.
Trap-assisted decay spectroscopy with ISOLTRAP
2012
Penning traps are excellent high-precision mass spectrometers for radionuclides. The high-resolving power used for cleaning isobaric and even isomeric contaminants can be exploited to improve decay-spectroscopy studies by delivering purified samples. An apparatus allowing trap-assisted decay spectroscopy has been coupled to the ISOLTRAP mass spectrometer at ISOLDE/CERN. The results from studies with stable and radioactive ions show that the setup can be used to perform decay studies on purified short-lived nuclides and to assist mass measurements. (C) 2012 Elsevier B.V. All rights reserved.