Optimization of a multi-ring detector for Ps time of flight measurements

16th International Conference on Positron Annihilation

Di Noto, L.^1 ; Benetti, M.^2 ; Mariazzi, S.^1 ; Dalla Betta, G.-F.^2 ; Brusa, R.S.^1

Dipartimento di Fisica, Università di Trento, Gruppo Collegato di Trento, Via Sommarive 14, Trento, I-38123 Povo, Italy^1

Dipartimento di Ingegneria e Scienza dell'Informazione, Università di Trento and INFN, Gruppo Collegato di Trento, Via Sommarive 14, Trento, I-38123 Povo, Italy^2

关键词: Acquisition time;    Back-scattered;    Background noise;    Bismuth germanate;    Figure of merits;    Silicon photomultiplier;    Three parameters;    Time of flight measurements;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/443/1/012074/pdf
DOI  :  10.1088/1742-6596/443/1/012074

来源: IOP

【 摘 要 】

We have designed a multi-ring detector (MRD) based on Bismuth Germanate (BGO) crystals, coupled to Silicon PhotoMultipliers (SiPM) for measuring the Ps time of flight (TOF). The set-up geometry was optimized by Monte Carlo simulations to take into account at different Ps velocities: (i) the background noise due to backscattered positrons, (ii) the crosstalk between adjacent detectors, (iii) the lifetime of Ps decay. Three parameters were defined to evaluate the different configurations and a figure of merit was obtained. This allows the choice of the best set up configuration for measuring Ps emitted with a particular energy range, optimizing the signal to noise ratio and keeping the acquisition time acceptable.