Screening Surface Contamination with BetaCage

Existing screening facilities are insufficiently sensitive to meet the needs of rare‐event experiments for low‐energy electron emitters and alpha‐decaying isotopes. To provide such screening, the BetaCage will be a low‐background, atmospheric‐pressure neon drift chamber with unprecedented sensitivity to emitters of low‐energy electrons and alpha particles. Minimization of the detector mass and use of radiopure materials reduce background events. The chamber design accepts nearly all alphas and low‐energy electrons from the sample surface while allowing excellent rejection of residual backgrounds. A non‐radiopure prototype is under construction to test the design. The BetaCage will provide new infrastructure for rare‐event science as well as for a wider community that uses radioactive screening for areas including archaeology, biology, climatology, environmental science, geology, planetary science, and integrated‐circuit quality control.