Fast timing: Lifetime measurements with LaBr(3) scintillators
Résumé
In order to perform half-life measurements at Alto, we developed a fast-timing setup using fast scintillators : LaBr(3). The main components of our setup and their characteristics (timing properties) are presented. The resulting time resolution, obtained after optimization, and measured off-line with radioactive sources is discussed. This set-up was tested on-line by measuring using the slope method half-lives of (137-138)CS levels fed by the beta(-) decay of (137-138)Xe. The neutron-rich Xe nuclei were produced by (238)U photofission using, at low intensity, the electron beam and the line of the future facility ALTO. Our results show the ability of such a fast-timing system to measure half-lives lower than the total time resolution. Off-line and on-line results are discussed.