0000000000087810
AUTHOR
R. Savreux
Cadmium mass measurements between the neutron shell closures at N=50 and 82
International audience; The mass values of the neutron-deficient cadmium isotopes 99−109Cd and of the neutronrich isotopes 114,120,122−124,126,128Cd have been measured using ISOLTRAP. The behavior of the separation energies of the cadmium isotopes from N = 50 to 82 is discussed.
Towards a magnetic field stabilization at ISOLTRAP for high-accuracy mass measurements on exotic nuclides
Abstract The field stability of a mass spectrometer plays a crucial role in the accuracy of mass measurements. In the case of mass determination of short-lived nuclides with a Penning trap, major causes of fluctuations are temperature variations in the vicinity of the trap and pressure changes in the liquid helium cryostat of the superconducting magnet. Thus systems for the temperature and pressure stabilization of the Penning trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN have been installed. A reduction of the temperature and pressure fluctuations by at least an order of magnitude down to Δ T ≈ ± 5 mK and Δ p ≈ ± 5 Pa has been achieved, which corresponds to a relative magn…
Time-separated oscillatory fields for high-precision mass measurements on short-lived Al and Ca nuclides
High-precision Penning trap mass measurements on the stable nuclide 27Al as well as on the short-lived radionuclides 26Al and 38,39Ca have been performed by use of radiofrequency excitation with time-separated oscillatory fields, i.e. Ramsey's method, as recently introduced for the excitation of the ion motion in a Penning trap, was applied. A comparison with the conventional method of a single continuous excitation demonstrates its advantage of up to ten times shorter measurements. The new mass values of 26,27Al clarify conflicting data in this specific mass region. In addition, the resulting mass values of the superallowed beta-emitter 38Ca as well as of the groundstate of the beta-emitte…
Approaching theN=82shell closure with mass measurements of Ag and Cd isotopes
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…
Magnetic field stabilization for high-accuracy mass measurements on exotic nuclides
The magnetic-field stability of a mass spectrometer plays a crucial role in precision mass measurements. In the case of mass determination of short-lived nuclides with a Penning trap, major causes of instabilities are temperature fluctuations in the vicinity of the trap and pressure fluctuations in the liquid helium cryostat of the superconducting magnet. Thus systems for the temperature and pressure stabilization of the Penning trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN have been installed. A reduction of the fluctuations by at least one order of magnitude downto dT=+/-5mK and dp=+/-50mtorr has been achieved, which corresponds to a relative frequency change of 2.7x10^{-…