Neutron Capture Cross Section Measurements for Nuclear Astrophysics at n_TOF

The neutron time of flight (n_TOF) facility at CERN is a neutron spallation source with a flight path of 187.5 m. Intense proton bunches from the CERN PS with an energy of 20 GeV, an intensity of 7×1012 protons per pulse, and a pulse width of 6 ns are focused on a lead spallation module. The white neutron energy spectrum produced in this way ranges from thermal to several GeV, thus covering the full energy range of interest for nuclear astrophysics, in particular for measurements of the neutron capture cross sections required in s-process nucleosynthesis. The combination of the long flight path of 187.5 m, which allows to perform time-of-flight measurements with very high energy resolution in a low-background environment, with the extremely high instantaneous neutron flux and the low repetition frequency of the proton beam is quite unique and perfectly suited for measurements of neutron capture cross sections in general and on radioactive samples in particular. This contribution gives an overview of the completed neutron capture studies on isotopes of Mg, Zr, La, Sm, Os, Pb, and Bi. Further improvements and future plans for nuclear astrophysics applications are addressed as well.JRC.D.5-Neutron physic