Speaker
Description
Recent advances in fast scintillators, high-performance photodetectors, and state-of-the-art readout electronics are driving substantial progress in both Nuclear Spectroscopy and Reaction Dynamics, and medical imaging. Halide-based inorganic scintillator crystals, which offer fast timing response, excellent energy resolution, and high effective atomic number, have proven particularly suited for lifetime measurements of nuclear excited states on the order of a few tens of picoseconds. HISTARS (HIE-ISOLDE Timing Array for Reaction Studies) is a detection system under construction aimed at lifetime measurements of excited states populated in reactions with accelerated radioactive ion beams at the HIE-ISOLDE facility at CERN. Nuclear excite-states lifetimes are essential have direct access to electromagnetic transition rates, which are sensitive to the details of nuclear wavefunctions. The idea is profiting from the versatility of the ISOLDE facility to deliver exotic isotope beams and the unique access to post-accelerated radioactive beams up to 10 MeV/u provided by HIE-ISOLDE.
HISTARS combines a charged particle inner detector system with enhanced capabilities for reaction tagging with excellent timing response and an external gamma fast-timing array based on LaBr3(Ce) detectors. The system aims to benefit from recent advancements in instrumentation and electronics, utilizing improvements in digital signal processing and innovative analysis techniques based on genetic algorithms.
To benchmark the performance of the instrumentation and to validate particle-gamma coincidence capabilities with fast scintillators, dedicated test experiments have been conducted using Coulomb-excitation reactions at the 5-MV tandetron at CMAM in Madrid. Various scintillator systems including GaGG(Ce), YSO, fast LGSO and plastic scintillators coupled to silicon photomultipliers (SiPMs), and reference LaBr$_3$(Ce) detectors have been employed. Further tests have been done under realistic beam pulsing conditions at HIE-ISOLDE using post-accelerated stable beams.
The presentation will outline the conceptual and technical design of HISTARS, supported by Monte Carlo simulations, and will showcase experimental results on scintillator timing and energy response. Preliminary results about the tests will be shared. Physics cases will also be discussed to illustrate the potential reach of this next-generation fast-timing detection system at HIE-ISOLDE.