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Using isochronous mass spectrometry at the experimental storage ring CSRe in Lanzhou, the masses of 82 Zr and 84 Nb were measured for the first time with an uncertainty of ∼10 keV, and the masses of 79 Y, 81 Zr, and 83 Nb were re-determined with a higher precision. The latter are significantly less bound than their literature values. Our new and accurate masses remove the irregularities of the mass surface in this region of the nuclear chart. Our results do not support the predicted island of pronounced low α separation energies for neutron-deficient Mo and Tc isotopes, making the formation of Zr–Nb cycle in the rp -process unlikely. The new proton separation energy of 83 Nb was determined to be 490(400) keV smaller than that in the Atomic Mass Evaluation 2012. This partly removes the overproduction of the p -nucleus 84 Sr relative to the neutron-deficient molybdenum isotopes in the previous νp -process simulations. [ABSTRACT FROM AUTHOR]

New mass values measured with the TITAN MR-TOF-MS are reported for the short-lived isotopes 24−26Ne, produced at TRIUMF's ISAC facility using a uranium carbide target and cold FEBIAD ion source. A least-squares adjustment within the framework of the Atomic Mass Evaluation was performed and the improved precision of the new mass values is highlighted. The improved mass accuracy in this N = 14 mid-shell region can also point to the refinement in values of the charge radii. By reducing the mass uncertainty of isotopes, their contribution of the mass shift uncertainty in laser spectroscopy can be negated. The work is part of developments for reaching the N = 20 Island of Inversion, where high molecular contamination hinders mass measurements of the neon isotopes. [ABSTRACT FROM AUTHOR]

Abstract: Accuracy of nuclear mass measurements in storage rings depends critically on the accuracy with which the revolution times of stored ions can be obtained. In such experiments, micro-channel plates (MCP) are used as timing detectors. Due to large phase space of injected secondary beams, a large number of ions cannot be stored in the ring and is lost within the first few revolutions. However, these ions interact with the detector and can saturate the MCP and thus deteriorate its performance. In order to eliminate such effects, a fast, pulsed high-voltage power supply (PHVPS) has been employed which keeps the detector switched-off during the first few revolutions. The new detector setup was taken into operation at the Experimental Cooler-Storage-Ring CSRe in Lanzhou and resulted in a significant improvement of the detector amplitude and efficiency characteristics. [Copyright &y& Elsevier]

Mass measurements of 49,50Sc, 70As, 73Br and 196Hg nuclides produced at CERN's radioactive-ion beam facility ISOLDE are presented. The measurements were performed at the ISOLTRAP mass spectrometer by use of the multi-reflection time-of-flight and the Penning-trap mass spectrometry techniques. The new results agree well with previously known literature values. The mass accuracy for all cases has been improved. [ABSTRACT FROM AUTHOR]