Timing characteristics of the R13089-100 photomultiplier tube coupled with 1.5" × 1.5" CeBr₃ scintillators and its application in lifetime measurements

The fast-timing performance of the Hamamatsu Photomultiplier Tube (PMT) model R13089-100 is investigated using 1.5" × 1.5" CeBr₃ scintillators. The time walk was measured using the Mirror-Symmetric Centroid Difference (MSCD) method for various PMT Bias voltages and CFD delays, to optimize the parameters for measurement of the lifetime of nuclear excited states via the γ-γ fast-timing technique. The ¹⁵²Eu and ¹³³Ba sources were used for investigation on timing characteristics. Lifetimes of 161 and 383 keV states of¹³³Cs from the decay of ¹³³Ba radioactive source have been determined for different bias voltages of PMT and CFD delays, with two 1.5" × 1.5" CeBr₃ detector setup. The lifetime of 1522 keV state of ²⁰⁹Po from the decay of ²⁰⁹At, produced from α induced fusion evaporation reaction, has also been determined. The results reported in the present paper show that the time resolution and time-walk characteristics of the Hamamatsu PMT R13089-100 can be improved in low-energy region using higher PMT bias voltage and shorter CFD delay.