Preparation of 137Cs-Loaded Silicotitanate Sealed Source and Standardization of Its Activity by DETEFF Code and Efficiency Transfer Concept

Resumo

A ¹³⁷Cs-loaded sealed source was prepared by contacting silicotitanate gel with a ¹³⁷Cs solution at pH 7 for 48 h at 25°C, drying at 100°C for 24 h, placing as a radioactive core inside a central cylindrical cavity in a base Perspex half-disc, and assembling a top Perspex half-disc with the base one using epoxy adhesive. The sealed source prepared was standardized using a γ-ray spectrometer and various calculation methods including DETEFF code and different ways of the efficiency transfer concept. For higher accuracy, the effect of the HPGe detector contamination background at different measurement distances was studied. The prepared sealed source was found to have a ¹³⁷Cs activity of 0.98 ± 0.06 kBq.