In this work, we present a fast and highly efficient method for the measurement of 210Pb in metallic archaeological lead using the commercial low-background liquid scintillation counter Wallac Quantulus 1220 installed at the University of Milano-Bicocca (Italy). By combining an optimized chemical preparation with pulse-shape analysis (PSA), the technique achieves sensitivities at the level of a few 102 mBq/kg within one week of measurement, using sample masses below 1 g. The method enables the simultaneous identification of the β decays of 210Pb and 210Bi and the α decay of 210Po, allowing a direct verification of secular equilibrium within the decay chain. With extended acquisition times, detection limits below 100 mBq/kg are reached after approximately 40 days. This approach provides a rapid, accessible, and reliable tool for the radiopurity screening of lead, and is well suited for quality control and R&D activities in next-generation low-background and rare-event physics experiments. Moreover, the method has the potential to be extended to other materials relevant for low-background applications.
@article{arxiv.2602.02674,
title = {A rapid low-background assay of $^{210}$Pb in archaeological lead},
author = {M. Consonni and M. Clemenza and E. Di Stefano and N. Ferreiro Iachellini and F. Filippini and A. Gardini and G. Grosso and L. Pattavina and R. Della Pergola and S. Quitadamo and E. Sala and F. Saliu and A. Salvini and L. Trombetta},
journal= {arXiv preprint arXiv:2602.02674},
year = {2026}
}