Fast inorganic scintillators – status and outlook

Scintillation detectors based on inorganic materials represent one of the most widely applied instrumentation techniques in the fields of nuclear and high-energy physics as well as medical or industrial applications. Driven by experimental requirements the research has focused onto a faster response, shorter decay times and higher compactness implementing high-Z ions. The discovery of the fast core-valence luminescence in BaF₂, the allowed electric dipole transitions in Ce³⁺, and the short radiation lengths of BGO and PbWO₄ have set important milestones. However, excellent time resolution is affected as well by the density of photoelectrons produced at the early stage of the signal generation and the integral light output. The paper will give a detailed overview of the present status on fast inorganic scintillators, their performance and the theoretical limitations on achievable energy and time resolutions. The results are illustrated by various applications in research. The state of the art scintillator material will be discussed based on new materials such as LaBr₃ or LaCl₃, which were doped with rare earth ions such as Ce³⁺-centers to reach decay times between 20 and 40ns, respectively.