Standardization of 68Ga by means of a 4πβ-γ Software Coincidence System

The present work aims the standardization of ⁶⁸Ga, a positron emitter of short half-life used in PET (Positron Emission Tomography). The ⁶⁸Ga standardization was performed in a triple 4πβ-γ coincidence system that consists of a thin window gas-flow proportional counter (PC) in 4π geometry coupled to a NaI(Tl) scintillator and a HPGe crystal, for gamma-ray detection. The data acquisition was carried out by means of a Software Coincidence System (SCS) developed at the Nuclear Metrology Laboratory (Laboratório de Metrologia Nuclear - LMN) at the IPEN-CNEN/SP. The final results were obtained from a multiple curve fitting applying a covariance matrix methodology combining experimental results with those determined by the Monte Carlo simulation.