Low‑Background Steel: Rare Material for Ultra‑Sensitive Measurements

Low‑background steel is steel manufactured before the first nuclear weapons tests. It contains only trace natural radioactivity. The material is prized for its exceptionally low background radiation. It is used in detectors for particle physics and dark‑matter experiments. Modern steel contains higher levels of anthropogenic isotopes such as cobalt‑60. The scarcity of pre‑1945 steel makes it a limited resource. Researchers often recycle old ship hulls and structures to obtain it. Conservation of low‑background steel is critical for precision experiments.