Search results for "Penn"
showing 10 items of 568 documents
The g Factor of Hydrogenic Ions: A Test of Bound State QED
2007
We present a new experimental value for the magnetic moment of the electron bound in hydrogenlike carbon (12C5+): g exp = 2.001 041 596 (5). The experiment was carried out on a single 12C5+ ion stored in a Penning trap. The high accuracy was made possible by spatially separating the induction of spin flips and the analysis of the spin direction. Experiment and theory test the bound-state QED contributions to the gJ factor of a bound electron to a precision of 1%. We discuss also implications of the experiment on the knowledge of the electron mass.
Precision mass measurements of neutron-rich Tc, Ru, Rh, and Pd isotopes
2007
The masses of neutron-rich $^{106\ensuremath{-}112}\mathrm{Tc}$, $^{106\ensuremath{-}115}\mathrm{Ru}$, $^{108\ensuremath{-}118}\mathrm{Rh}$, and $^{112\ensuremath{-}120}\mathrm{Pd}$ produced in proton-induced fission of uranium were determined using the JYFLTRAP double Penning trap setup. The measured isotopic chains include a number of previously unmeasured nuclei. Typical precisions on the order of 10 keV or better were achieved, representing a factor of 10 improvement over earlier data. In many cases, significant deviations from the earlier measurements were found. The obtained data set of 39 masses is compared with different mass predictions and analyzed for global trends in the nuclear…
Status of REX-ISOLDE
2003
REX-ISOLDE [1] is a post-accelerator situated at the ISOLDE radioactive ion beam facility placed at CERN, Geneva. It’s main aim is to increase the energy of light (A < 50) radioactive ions from 60 keV to 0.8–2.2MeV/u. REX—ISOLDE uses a new concept of post-acceleration of radioactive ion beams by using charge breeding of the ions in a high charge state ion source and the efficient acceleration of the highly charged ions in a short LINAC using modern ion accelerator structures. In a first step the radioactive ions are captured in a large gas-filled Penning trap. The task is to accumulate, cool and bunch the beam and prepare it for the injection into an electron beam ion source (EBIS). Cooling…
Penning-trap mass measurements of neutron-deficient Rb and Sr isotopes
1993
Abstract The Penning-trap mass spectrometer ISOLTRAP installed at the on-line mass separator ISOLDE 2 at CERN has been used for mass determination of 75–87 Rb and 78–83,87 Sr. Ions are captured in a Penning trap and their cyclotron frequency ω c = ( q m )B in the trapping field B is measured. Ratios of these frequencies lead to the determination of the atomic mass of these isotopes. A resolving power of typically m Δm = 10 6 and an accuracy of δm ≈10 keV is obtained. The mass of 78 Sr is measured for the first time and, in most cases, the mass values of the other isotopes are significantly improved. The experimental masses are compared with theoretical predictions.
High-precision masses of neutron-deficient rubidium isotopes using a Penning trap mass spectrometer
2007
The atomic masses of the neutron-deficient radioactive rubidium isotopes $^{74-77,79,80,83}$Rb have been measured with the Penning trap mass spectrometer ISOLTRAP. Using the time-of-flight cyclotron resonance technique, relative mass uncertainties ranging from $1.6 \times 10^{-8}$ to $5.6 \times 10^{-8}$ were achieved. In all cases, the mass precision was significantly improved as compared with the prior Atomic-Mass Evaluation; no significant deviations from the literature values were observed. The exotic nuclide $^{74}$Rb with a half-life of only 65 ms, is the shortest-lived nuclide on which a high-precision mass measurement in a Penning trap has been carried out. The significance of these…
Systematic studies of the accuracy of the Penning trap mass spectrometer JYFLTRAP
2009
Abstract Measurements to quantify the mass-dependent systematic effect and the residual uncertainty of the JYFLTRAP setup have been performed with carbon-cluster ions. The primary quantities reported in this work are a mass-dependent uncertainty of σ m ( r ) / r = ( 7.8 ± 0.3 × 10 - 10 / u ) × Δ m and a residual uncertainty of σ res ( r ) / r = 1.2 × 10 - 8 for the JYFLTRAP mass spectrometer. By restricting the mass difference between the reference ion and ion of interest to | m meas - m ref | ≤ 24 , the values for the mass-dependent effect and the corresponding residual uncertainty are σ m , lim ( r ) / r = ( 7.5 ± 0.4 × 10 - 10 / u ) × Δ m and σ res , lim ( r ) / r = 7.9 × 10 - 9 , respec…
Accurate masses of neutron-deficient nuclides close to
2001
Abstract Mass measurements with the Penning-trap mass spectrometer ISOLTRAP at ISOLDE/CERN are extended to nonsurface ionizable species using newly developed ion-beam bunching devices. Masses of 179–197Hg, 196,198Pb, 197Bi, 198Po and 203At were determined with an accuracy of 1×10 −7 corresponding to δm≈20 keV. Applying a resolving power of up to 3.7×10 6 ground and isomeric states of 185,187,191,193,197Hg were separated. First experimental values for the isomeric excitation energy of 187,191Hg are obtained. A least-squares adjustment has been performed and theoretical approaches are discussed to model the observed fine structure in the binding energy.
Adiabatic cooling of antiprotons in a Penning trap
1993
An antiproton cloud cooled at 4.2 K in a Penning trap can be further cooled by adiabatic reduction of the trap magnetic and electric fields. It will be shown that the temperature can be reduced by two orders of magnitude. This cooling method may be useful to obtain ultra-low energy antiprotons for the measurement of their gravitational properties and the production of ultra-low energy antihydrogen atoms.
Double-beta decay Q values of 116Cd and 130Te
2011
Abstract The Q values of the 116Cd and 130Te double-beta decaying nuclei were determined by using a Penning trap mass spectrometer. The new atomic mass difference between 116Cd and 116Sn of 2813.50(13) keV differs by 4.5 keV and is 30 times more precise than the previous value of 2809(4) keV. The new value for 130Te, 2526.97(23) keV is close to the Canadian Penning trap value of 2527.01 ± 0.32 keV (Scielzo et al., 2009) [1] , but differs from the Florida State University trap value of 2527.518 ± 0.013 keV (Redshaw et al., 2009) [2] by 0.55 keV (2σ). These values are sufficiently precise for ongoing neutrinoless double-beta decay searches in 116Cd and 130Te. Hence, our Q values were used to …
Production and trapping of carbon clusters for absolute mass measurements at ISOLTRAP
2001
Singly-charged carbon clusters C/sub n//sup +/ (n >or= 1) have been produced by laser-induced desorption and fragmentation of C/sub 60/ fullerenes and have been injected into and stored in the Penning trap system of the ISOLTRAP mass spectrometer at ISOLDE/CERN. The present study is the first step to extend the until now direct mass measurements at ISOLTRAP to absolute mass measurements by using clusters of /sup 12/C. (10 refs).