In the present study, all dosimetry parameters around the ۲۵۲Cf Isotron source for neutron brachytherapy were calculated.
The ۲۵۲Cf neutron energy spectrum was modeled using the Maxwellian spectrum. The calculations were performed using
MCNPX.۲.۶.۰ code based on the TG-۴۳U۱ protocol in the water medium. The neutron air kerma strength for the ۲۵۲Cf
Isotron source was computed as ۰.۳۰۹۸ ± ۰.۰۰۰۲ cGy cm۲/μgh and the neutron dose rate constant was ۶.۵۵۹ ± ۰.۰۰۳
cGy/Uh. The anisotropy functions were calculated at intervals of ۱, ۲, ۳, ۴, and ۵cm at different polar angles in the
range of θ = ۰̊ to ۹۰º in respect to the source long axis in a water Phantom. The uncertainty of the calculated data at all
distances is less than ۱%. The radial dose function at different distances from the source for the Isotron model was
compared with the theoretical HDR ۲۵۲Cf source model. The discrepancies between the results were the highest at the
distance of ۰.۵ cm, with relative differences of ۵.۶۴ %. For the ۲۵۲Cf Isotron source, the data presented in this study
provides better understanding on the dosimetric distribution of a theoretical neutron brachytherapy source, for potential
clinical application