Commissioning of the BRIKEN detector for the measurement of very exotic ß-delayed neutron emitters

A new detection system has been installed at the RIKEN Nishina Center (Japan) to investigate decay properties of very neutron-richnuclei. The setup consists of three main parts: a moderated neutron counter, a detection system sensitive to the implantation anddecay of radioactive ions, and γ-ray detectors. We describe here the setup, the commissioning experiment and some selected resultsdemonstrating its performance for the measurement of half-lives andβ-delayed neutron emission probabilities. The methodologyfollowed in the analysis of the data is described in detail. Particular emphasis is placed on the correction of the accidental neutronbackground.Postprint (author's final draft