A measurement of the neutron capture cross sections of 186Os, 187Os, and 188Os.

•Marita Mosconi
for the n_TOF collaboration

The radiative neutron capture cross sections of 186Os and 187Os have fundamental importance for the analysis of the Re/Os cosmochronometer. These data allow one to discriminate the amount of 187Os producted by nucleosynthesis from the one generated by radioactive decay of 187Re, an information related to onset of nucleosynthesis of the heavy elements.
The capture cross sections of the three stable isotopes 186Os,187Os, and 188Os have been measured at the CERN n_TOF facility in the energy range from 1 eV to ~ 1 MeV. This contribution reports on preliminary cross section results.