A new AMS setup for nuclear astrophysics experiments

The Nuclear Structure Laboratory (NSL) at the University of Notre Dame installed its Browne–Buechner spectrograph in the early 1970s for highly accurate energy measurements of nuclear reactions. Current renovation and upgrading of this spectrograph will enable operation of the magnet in a gas-filled mode, in particular for the study of nuclear reactions with low cross-sections of interest in nuclear astrophysics. One of the principle issues shared by measurements of extremely low abundances in Accelerator Mass Spectrometry (AMS) and nuclear astrophysics is the discrimination between the nuclei of interest and often very intense isobaric background. Recently the AMS technique of the gas-filled magnet has very successfully been used at Argonne National Laboratory (ANL) to overcome this in the study of both environmental noble gas traces ( 39 Ar) and the measurement of cross-sections of interest in stellar nucleosynthesis i.e. the 62 Ni( n , γ) 63 Ni reaction. We hope to extend these techniques further to the observations of astrophysically important reactions such as 40 Ca(α, γ) 44 Ti and 78 Kr(α, γ) 82 Sr.