Ponente
Descripción
Scintillators and photodetectors for fast timing are transforming various research fields. Innovative scintillator crystals built from LaBr$_3$(Ce), co-doped LaBr$_3$ and CeBr$_3$ compounds, unite excellent time response, good energy resolution, and relatively high effective Z. They are highly advantageous for radioactive ion beam experiments, enabling fast-timing experiments that can accurately measure nuclear state lifetimes, even in the range down to tens of picoseconds. In these experiments, the lifetimes of nuclear levels are determined through fast electronic coincidences between the radiation that populates and de-excites a given nuclear level.
On the other hand, faster scintillators allow replacing the present generation of LSO or LYSO-based PET scanners, and improving the achievable time resolution for TOF-PET. Moreover, short decays times will be able to sustain higher rates enhancing the sensitivity of modern preclinical scanners.
In this contribution we will discuss the instrumentation, readout electronics and the digitization methods for fast-timing measurements, and it will illustrate its use in nuclear spectroscopy experiments. We will report on the experimental investigation of the time and energy response of detectors based on inorganic scintillators with strong potential for fast timing and imaging applications, including LaBr$_3$(Ce), CeBr$_3$ and co-doped LaBr$_3$(Ce+Sr) scintillators. The performance of custom crystals, specially designed for timing measurements, is also described.
We will also address electronic readouts based on Silicon Photomultipliers (SiPMs) which exhibit high photon detection efficiency, are insensitive to magnetic fields, and are also intrinsically fast. In this work we investigate the time and energy resolution achieved with the relatively large scintillator crystals coupled to suited SiPMs and compare them to those obtained with photomultiplier-tube readout.
We fill further discuss digital signal processing for the fast signals from the scintillator detectors. Although digital processing is gaining weight as data acquisition in multi-parameter set-ups, digital methods able to recover the excellent intrinsic time resolution of fast scintillators are still not widely available yet. We present results of digital acquisition and processing strategies, and compare them to analogue electronics. We show that digital processing using automatic processing and deep learning methods is a competitive technique for fast scintillators.
Finally, examples of the capabilities of ultrafast detectors to handle high count rates, thereby improving the performance of modern preclinical PET scanners, and applications in hadrontherapy monitoring will be provided.
