Optimizing the operating condition of LaBr₃ (Ce) - R2083 PM tube system with VME-based DAQ for fast timing application

In nuclear physics experiments, there are various standards for data acquisition systems (DAQ). The Versa Module Europa (VME) bus is an asynchronous, parallel bus which is highly effective in intense computing tasks. VME bus offers a backplane that provides fast data transfer allowing an increased amount of data. On the other hand, the detector used in the work is LaBr₃ (Ce) detector which due to its excellent energy resolution of ~3% at 662 keV Gamma line and short decay time (between 20-30 ns ), is presently one of the best choice among the various scintillators for fast timing application. The LaBr₃ (Ce) detector coupled to a fast Photomultiplier (PM) Tube Hamamatsu R2083 used in a VME DAQ is expected to yield an excellent time resolution (TR) and can be used in handling an increased amount of data or a high count rate. The high voltage to be applied to the detector system is the most important parameter to achieve the best TR in the linear energy response regime for the detector system. In the present work, 1 in. x 1 in. 5% Ce-doped LaBr₃ crystals coupled to fast Hamamatsu R2083 PMT has been characterized in VME DAQ system. The energy as well as the timing properties for the LaBr₃ (Ce)-R2083 assembly has been explored in VME DAQ at bias voltages ranging from -2.0 KV to -2.8KV using various radioactive sources like ⁶⁰Co, ¹⁵²Eu, ¹⁰⁶Ru