A sensitive mapping technique for bismuth using α-particle tracks

Bi-containing metals, minerals, and glasses were irradiated with thermal neutrons to produce the isotope 210Po from the reaction 209Bi(n,γ)210Bi (β-→ 210Po. After n-irradiation the Bi microdistributions in the samples were recorded in cellulose nitrate and cellulose triacetate by α-track radiography using the induced 210Po α-activity. The possible interference of U and Th and their decay series is discussed and taken into account. The ultimate Bi-detection limit was found to be ca. 10 ppb, and the spatial resolution achievable at Bi concentrations in the ppm range is approximately 10 μm. (Auth.)