Characterisation of OSL and OSLN droplets for dosimetry

In spite of considerable progress in neutron dosimetry, there is no dosemeter that is capable of measuring neutron doses independently of the neutron spectrum with good accuracy. Carbon-doped aluminium oxide (Al₂O₃:C) is a sensitive material for ionising radiation (beta-ray, X ray and electron) and has been used for applications in personal and medical dosimetry as an optically stimulated luminescence (OSL) dosemeter. Al₂O₃:C has a low sensitivity to neutron radiation; this prevents its application to neutron fields, representing a disadvantage of Al₂O₃:C-OSL when compared with LiF, which is used as a thermoluminescent detector. Recently an improvement for neutron dosimetry (Passmore and Kirr. Neutron response characterisation of an OSL neutron dosemeter. Radiat. Prot. Dosim. 2011;144:155-60) uses Al₂O₃:C coated with ⁶Li₂CO₃ (OSLN),which gives the highsensitive response as known for Al₂O₃:C with the advantage of being also sensitive to thermal neutrons. In this article, the authors compare small-size detectors (droplets) of Al₂O₃:C (OSL) and of Al₂O₃C+⁶Li₂CO₃ (OSLN) and discuss the advantages and drawbacks of both materials, regarding size vs. response.