Commissioning and performance of IDATEN: A large fast-timing <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si33.svg" display="inline" id="d1e332"> <mml:mi>γ</mml:mi> </mml:math> -ray detector array at the RIBF

A large fast-timing γ-ray detector array has been newly developed under the International Detector Assembly for fast-Timing measurements of Exotic Nuclei (IDATEN) project. The full IDATEN array comprises 82 LaBr3(Ce) γ-ray detectors, of which 46 and 36 are provided by the KHALA and FATIMA collaborations, respectively. To assess the fast-timing performance of this large-scale system with stopped rare-isotope beams, a commissioning experiment was recently carried out at the Radioactive Isotope Beam Factory (RIBF) at RIKEN. Neutron-deficient rare isotopes near 100Sn were produced via in-flight fragmentation of a 124Xe primary beam. The fast-timing capability was evaluated using 96Pd as the reference nucleus by measuring the half-lives of the 21+, 41+ and 61+ levels, which were populated through the decay of the long-lived 81+ isomeric state. These results demonstrate the reliability of our experimental setup, including the readout electronics and data acquisition system, thereby validating its readiness for forthcoming physics experiments at the RIBF. Moreover, the measured half-life values are in agreement with previously reported literature values, with some determinations achieving improved precision.