Radioactive contamination of BaF2 crystal scintillator

Barium fluoride (BaF2) crystal scintillators are promising detectors to search for double beta decay processes in 130Ba (Q2β = 2619(3) keV) and 132Ba (Q2β = 844(1) keV). The 130Ba isotope is of particular interest because of the indications on 2β decay found in two geochemical experiments. The radioactive contamination of BaF2 scintillation crystal with mass of 1.714 kg was measured over 113.4 hours in a low-background DAMA/R&D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of 212Po (present in the crystal scintillator due to contamination by radium) was estimated as T1/2 = 298.8 ± 0.8(stat.) ± 1.4(syst.) ns by analysis of the events pulse profiles.