The influence of unstable signals for electron spin resonance dosimetry with synthetic A-type carbonated apatite.

Synthetic A-type carbonated apatite prepared in controlled conditions was irradiated at room temperature with 60Co gamma rays. The ESR spectrum was associated to axial CO2- and orthorhombic CO3- species. Radicals used as dose markers in biological apatites are long-lived paramagnetic species. The stability of the post-irradiation signal of A-type apatite was investigated for almost 2 years. Measurements showed variations in the spectra attributed to unstable CO3- species, which can be eliminated by thermal treatments at 100 degrees C for 24 h. Results indicated the potential use of an A-type carbonated apatite as a dosemeter.