Neutron capture- and fission-reaction cross sections for applications in nuclear astrophysics, advanced nuclear technologies, and basic nuclear physics have been the main objectives of the experimental activities performed at the neutron time-of-flight facility, n_TOF, at CERN, during the first three years of its operation. n_TOF is a spallation neutron source based on the 20-GeV proton beam of the CERN PS accelerator. The high intensity, wide-energy secondary neutron beam has been used for measurements on stable as well as on radioactive targets. The main advantages of the extremely high instantaneous neutron flux is for measurements of reaction cross sections on radioactive samples. In addition, the 200m flight-path of the neutron beam line allows for extremely high-resolution neutron resonance spectroscopy.

After the description of the facility and of the experimental setup, the results of the measurements of neutron capture reactions relevant for s-process nucleosynthesis will be presented. In particular, the implications of the capture measurements on Sm-151 (s-process branching), La-139 (s-process indicator in metal-poor stars), and of the Os istopes (Re/Os cosmo-chronology) will be discussed.

The n_TOF Collaboration has identified the physics cases and a set of experiments which constitutes the plan for "Phase 2" of the activities to be performed at n_TOF, from 2007 and beyond. An outline of this plan, together with the perspectives for developments foreseen for the facility will be presented.

ANL Physics Division Seminar Schedule