Removal of 210Pb by etch of crystalline detector sidewalls

Abstract A potential source of dominant backgrounds for many rare-event searches or screening detectors is from radon daughters, specifically 210Pb, deposited on detector surfaces, often during detector fabrication. Performing a late-stage etch is challenging because it may damage the detector. This paper describes a late-stage etching technique that reduces surface 210 Pb and 210 Po by > 99 × at 90% C.L.