On contamination of Bi4Ge3O12 single crystals with 207Bi isotope

Abstract

Two versions of generation of ²⁰⁷Bi radionuclide are known from the literature: natural phenomena (cosmic rays) and technogenic factors (high-power nuclear weapons tests). The amounts of the generated radionuclide are so large that it can be detected even in Bi₄Ge₃O₁₂ (BGO) scintillator. Previously we demonstrated that natural phenomena cannot generate these amounts of ²⁰⁷Bi. The identification of ²⁰⁷Bi of cosmic origin in BGO is doubtful. BGO crystals are inevitably contaminated with isotopes from natural radioactive series, which are significant components of the background radiation of the Earth. Contamination with ²²⁷Ас due to several factors is possible. The decay of ^211+211mPo to the energy levels of ^207mPb can be misinterpreted as the ²⁰⁷Bi decay.