ARIES: A new High-Efficiency, High-Granularity Beta-Tagging scintillator array with Ultra-Fast Timing capabilities for Decay Spectroscopy Studies.

The combination of large arrays of high-purity germanium (HPGe) detectors with auxiliary particle detection systems is among the most powerful methods for studying atomic nuclei. It is done through nuclear spectroscopy at radioactive ion beam facilities such as TRIUMF-ISAC together with the use of high-efficiency gamma-ray spectrometers like GRIFFIN (The Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei).

The use of ancillary detectors is key for disentangle complex level schemes, providing high isotopic selectivity and giving access to physics observables which provide direct insight to the nuclear structure.

The ARIES detector (Ancillary Detector for Rare-Isotope Event Selection) is a high-efficiency ultra-fast β-particle detector designed to operate as the main ancillary detector of the GRIFFIN spectrometer. Its design matches 1:1 the GRIFFIN geometry, allowing the study of b-g angular correlations with more than 114 unique angles. ARIES entails low g-ray attenuation, superior counting rate for a source with an activity greater than 20MBq and Ultra-Fast Timing capabilities allowing lifetime measurement down to the few ps range.

In addition to the novel design, it also leverages modern technologies such as flex-circuit electronics, magnetron sputtering for reflector-coating the plastic scintillators and many more.

The design, performance and status of ARIES along with an overview of the scientific opportunities will be presented.