Speaker
Description
The HYPATIA (HYbrid Photon detector Array To Investigate Atomic nuclei) [1] is an array under construction at the RIBF that consists of GAGG and CeBr3 scintillator crystals coupled to large area SiPM photosensors. In particular, the Hamamatsu S14161-6050HS-04 4x4 SiPM array. Excellent timing response from HYPATIA is important for reducing the non-prompt background induced by particles emitted during nuclear reactions, and for performing fast-timing lifetime measurements. Connecting SiPM pixels in parallel results in a large total capacitance, broadening the signal’s rise time and degrading the time resolution. Therefore, careful consideration needs to be paid to how the pixel signals are summed. Several methods have been successfully used to achieve fast timing with SiPM photosensors [2,3]. However, they typically produce a slow and a fast signal, requiring two DAQ channels per detector and introducing additional complexity. Other methods for summing have also been developed using multiple op-amps to sum the signals, such as in [4]. However, the use of many op-amps requires a large PCB and produces heat. To address this, a fast-timing circuit has been developed using a sum-amplifier circuit with a single op-amp and a single output. In this contribution, we will present the circuit's performance with a small LaBr3 detector in comparison to a simple circuit with the pixels connected in parallel. In addition, the results from GAGG and CeBr3 detectors will be presented.
[1] P. Doornenbal, et al. The HYPATIA Project, RIBF NP-PAC-24, (2023)
[2] S. Dolinsky, et al. IEEE NSS/MIC, (2013), 1-6
[3] C. Mihai, et al. NIM A, 953, (2020), 163263
[4] C. M. Lavelle, et al. AIP Advances, 9, (2019), 035123