Characterization of coincidence time resolutions of TlBr (x) Cl1-x crystals as Cherenkov radiators

The coincidence time resolutions of thallium bromide chloride (TlBr x Cl1-x ) crystals used as Cherenkov radiators were characterized. A pair of TlBr x Cl1-x crystals with the same composition was used to coincidentally detect positron annihilation gamma rays from a Na-22 source. The size of the crystals was approximately 3 mm x 3 mm x 3 mm. A polished surface of the crystals was coupled to a silicon photomultiplier. The time resolution improved with an increase in the Cl concentration in the crystals. TlBr0.3Cl0.7 crystals exhibited the best coincidence time resolutions of 378 & PLUSMN; 17 ps and 635 & PLUSMN; 31 ps with and without event selection based on the photoelectron level, respectively.

Automated summary

The coincidence time resolutions of thallium bromide chloride (TlBr x Cl1-x ) crystals used as Cherenkov radiators were evaluated. A pair of TlBr x Cl1-x crystals with the same composition were simultaneously used to detect positron annihilation gamma rays from a Na-22 source. The crystals had dimensions of approximately 3 mm x 3 mm x 3 mm, and their polished surfaces were coupled to silicon photomultipliers. The time resolution improved as the chlorine concentration in the crystals increased. TlBr0.3Cl0.7 crystals exhibited the best coincidence time resolutions of 378 ± 17 ps and 635 ± 31 ps with and without event selection based on the photoelectron level, respectively.