Probing the structure of short-lived nuclei with single-nucleon transfer reactions is a key focus of existing and emerging radioactive-ion-beam facilities. There has been a great deal learnt in exploiting these types of reactions with precision stable ion accelerators and high-resolution magnetic spectrometers over the past 50 years. Arguably, these data form the basis of our understanding of single-particle structure in stable and near-stable nuclei. Still today, interesting facets of nuclear structure are being tested with reactions using stable beams and targets, such as the hitherto unappreciated role of tensor force, which appears to drive the dramatic changes seen in exotic nuclei, and constraining matrix elements for neutrinoless double beta decay.
As we move into the radioactive ion beam domain, these reactions have to be performed in so-called inverse kinematics where heavy radioactive ion beams impinge light stable targets. In this regime there are numerous obstacles to overcome, not least the low intensity of radioactive ion beams---often many orders of magnitude weaker than stable ion beams. Though these studies are highly challenging, pioneering measurements have been made from studies at GSI in the early nineties, followed by those at Argonne in the late nineties and Oak Ridge just a few years ago. The single biggest experimental challenge is to overcome the dramatically poor resolution brought on by kinematic effects. This often hampers attempts to extract key data and typically we have to rely on composite detection systems, which can greatly reduce the efficiency and scope of the measurement. Recent efforts at Argonne have demonstrated a technique that achieves a superior resolution over conventional approaches opening up many exciting possibilities when coupled to the beams that will soon be available from the CARIBU upgrade to the ATLAS accelerator.
Argonne Physics Division Colloquium Schedule