Classification of mixed-radiation fields using the vector representation of thermoluminescent glow curves

A novel and robust technique, vector representation (VR), was developed for classifying the glow curves of thermoluminescent dosimeters (TLDs) exposed to proton, photon, and mixed proton-photon fields produced by two types of TLDs:LiF:Mg,Ti (TLD-100) and CaF2:Tm (TLD-300). Vectors were constructed from glow curve points and classified based on the TL vector inner product with a unit vector and TL vector magnitude. The goal was to perform two-category (proton or mixed/photon) and three-category (proton, photon, or mixed) classification. The method was tested for accuracy using leave-one-out validation (LOOV) with classification based on the smallest Mahalanobis distance. Using the high-temperature peaks of each material, correct classification rates exceeding 92% in all cases were obtained.