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Abstract: The Magnet for Astrophysical Nucleosynthesis studies Through Isobar Separation (MANTIS) system is the new Accelerator Mass Spectrometry (AMS) set-up created during recent upgrades of the Browne–Buechner spectrograph at the University of Notre Dame. Commissioning measurements performed on the separation of 58Fe–58Ni isobars at 114MeV out of the FN tandem accelerator have shown clear separation, opening the door for a number of future measurements in nuclear astrophysics. The separation of mass-58 isobars has made this system the first in the world to utilise a Browne–Buechner spectrograph in gas-filled mode for AMS measurements with a special focus on nuclear astrophysics. [Copyright &y& Elsevier]

The relatively short-lived radionuclide 44Ti is of considerable importance for the interpretation of nucleosynthesis in core-collapse supernova environments. Production is predominantly through the 40Ca(α,γ)44Ti reaction, which has been studied in this work over the energy range Ecm = 2.73--4.18 MeV, via direct γ counting and the 4π-summing technique, utilizing a previously characterized 12 inch × 12 inch single Nal crystal. The inferred reaction rate is compared here to both current experimental measurements and theoretical model calculations [ABSTRACT FROM AUTHOR]

Abstract: The extinct p-process nuclide 146Sm (t 1/2 =103±5Myr) is known to have been present in the Early-Solar System and has been proposed as an astrophysical chronometer. 146Sm is also intensely used to date meteorite and planetary differentiation processes, enhancing the importance of an accurate knowledge of the 146Sm half-life. We are engaged in a new determination of the 146Sm half-life in which the 146Sm/147Sm atom ratio is determined by accelerator mass spectrometry at the ATLAS facility of Argonne National Laboratory. In order to reduce systematic errors in the AMS determination of the 146Sm/147Sm ratios (in the range of 10−7–10−9), 146Sm and 147Sm ions were alternately counted in the same detector in the focal plane of a gas-filled magnet, respectively in continuous-wave and attenuated mode. Quantitative attenuation is obtained with the 12MHz pulsed and ns-bunched ATLAS beam by chopping beam pulses with an RF sweeper in a ratio (digitally determined) down to 1:106. The experiments and preliminary results are discussed. [Copyright &y& Elsevier]