Speaker
Description
Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) is a high-efficiency gamma-ray spectrometer designed for use in decay spectroscopy experiments with low-energy radioactive ion beams provided by TRIUMF’s Isotope Separator and Accelerator (ISAC-I) facility in Vancouver, Canada. The 16 Compton suppressed HPGe clover detectors are complemented by a fast-timing array consisting of 8 cerium-doped lanthanum bromide detectors (LaBr$_{3}$(Ce)) and a fast $\beta$ plastic scintillator mounted at 0° to the beam axis. With a hybrid digital-analog DAQ, the system has been shown to achieve a $\gamma$-$\gamma$ timing resolution of $\approx$ 330 ps FWHM, with a time walk of $\pm$ 60 ps across the 244–1299 keV energy range [1]. The setup enables simultaneous application of both the Advanced Time-Delayed $\beta\gamma\gamma(t)$ (ATD) method and the Generalized Centroid Difference Method (GCDM) to $\beta$-decay studies, providing access to nuclear excited state lifetimes down to the picosecond range [2-5]. Recent developments include the commissioning of ARIES (Ancillary Detector for Rare-Isotope Event Selection), a high-efficiency $\beta$-particle detector combining ultra-fast plastic scintillators and Silicon Photomultipliers (SiPM) that will broaden the scope of the fast-timing program at GRIFFIN. This talk will give an overview of the current and future capabilities of the fast-timing array, followed by a discussion of recent results.
[1] A.B. Garnsworthy et al. In: Nucl. Inst. Meths. A 918 (2019), pp. 9–29
[2] H. Mach, R.L. Gill, and M. Moszyński. In: Nucl. Inst. Meths. A 280 (1989), pp. 49–72.
[3] M. Moszyński and H. Mach. In: Nucl. Inst. Meths. A 277 (1989), pp. 407–417.
[4] H. Mach et al. In: Nucl. Phys. A 523 (1991), pp. 197–227.
[5] J.-M. Régis et al. In: Nucl. Inst. Meths. A 726 (2013), pp. 191–202.