From Bq cm⁻³ to Bq cm⁻² (and conversely)—part 1: a useful conversion for autoradiography

Autoradiography technique generally provides an image in cps cm⁻², the conversion in Bq g⁻¹ remaining a challenge. The Geant4 tool has been used to establish a conversion procedure based on the estimation of a key parameter, the emission fraction F_E. The conversion method was applied on three samples containing ³H, ¹⁴C and ²³⁸U respectively, allowing then to assess the detection efficiency of a digital radioimager, BeaQuant™. Particular attention was paid to matrix effect of contaminated material that could affect the detection efficiency. This article is coupled with a companion paper, providing support to apply the conversion method to decommissioning investigations.