The void fraction is one of the most important parameters characterizing a multiphase flow. The prediction
of the performance of any system operating with more than single phase relies on our knowledge and ability
to measure the void fraction. In this work, a validated simulation study was performed in order to predict the
void fraction independent of the flow pattern in gas-liquid two-phase flows using a gamma ray 60Co source
and just one scintillation detector with the help of an artificial neural network (ANN) model of radial
basis function (RBF). Three used inputs of ANN include a registered count under Compton continuum and
counts under full energy peaks of 1173 and 1333 keV. The output is a void fraction percentage. Applying
this methodology, the percentage of void fraction independent of the flow pattern of a gas-liquid two-phase
flow was estimated with a mean relative error less than 1.17%. Although the error obtained in this study
is almost close to those obtained in other similar works, only one detector was used, while in the previous
studies at least two detectors were employed. Advantages of using fewer detectors are: cost reduction and
system simplification.