Timing property of undoped BaCl₂ single crystal scintillator

Scintillation characteristics of undoped BaCl₂, a novel fast scintillation material, were investigated. Scintillation photons with wavelength ranging from 250-600 nm were observed with two luminescence bands at 300 and 400 nm. The scintillation time profiles consisted of two lifetime components. The shorter component had a lifetime of 1.6 ns, while the longer one had a lifetime of several tens of nanoseconds. The origin of the fast component has been attributed to self-trapped excitons, whereas the slow component is considered to be an extrinsic luminescence. The photoelectron yield of the fast component of BaCl₂ coupled to a bialkali photocathode was comparable to that of BaF₂. This shows that BaCl₂ is a promising scintillation material that can be used for measurements at a high counting rate or with an excellent timing property.