Calibration of a Poly Allyl Diglycol Carbonate (PADC) based track-etched dosimeter in thermal neutron fields

The purpose of this work was to study the response of a Poly Allyl Diglycol Carbonate (PADC) based neutron dosimeter in thermal fields. The dosimeter was irradiated in three different thermal piles, which are characterized by a homogeneous thermal field with a low proportion of fast neutrons. However, the dosimeter is highly sensitive to fast neutrons and, then, differences in the amount of fast neutrons arriving to the sensitive side of the dosimeter, which depends on the measurement point inside the pile and its orientation, can lead to differences in the response of the system. As an example, in one of the thermal piles, the response of the dosimeter ranged from (8.31 ± 0.44) × 10−6 tracks per neutron in a point with a 10% of fast neutrons to (2.27 ± 0.27) × 10−6 tracks per neutron in a point with an almost pure thermal field. This effect has the advantage that it is possible to choose conveniently a specific position inside the cavity where the neutron field spectrum is closest to the field where the dosimeter will be exposed, allowing to obtain the appropriate calibration factor.