“…Small-sized aliquots, 2 mm in diameter (i.e., containing some hundreds of grains), of quartz and K-feldspar grains were placed on stainless-steel discs using silicon oil as adhesive and stainless-steel cups. The quartz OSL signal was measured with the standard SAR protocol (Murray and Wintle, 2000, 2003), while K-feldspar grains were measured with the protocols, pIRIR 225 (Thiel et al, 2010, 2015; Ferranti et al, 2021) and pIRIR 290 (Buylaert et al, 2012; Thiel et al, 2012; Zucca et al, 2014a; Andreucci et al, 2017b; Casini et al, 2020; Sechi et al, 2020). To detect the portion of interest of OSL-quartz signal to calculate the equivalent dose (De), the first second (s) of signal decay was taken to which the following 2.6 s were subtracted as background (early background, i.e., Cunningham and Wallinga, 2010), whereas the first 5 s were subtracted by the last 20 s (late background) for pIRIR signal.…”