Characterisation of the secondary neutron field generated by a compact PET cyclotron with MCNP6 and experimental measurements.

The production of the most common used PET radioisotope Fluorine-18 with commercial cyclotrons is obtained from the 18O(p,n)18F nuclear reaction when 18O-enriched water is bombarded with a proton beam. We present the characterization of the secondary neutron field spectra produced by this reaction in different locations around the cyclotron, through a comparison between MCNP6 Monte Carlo simulation results and experimental data obtained with Neutron Activation Analysis (NAA) of thin target foils of different materials.