Impact of Thermal Treatment on Thermoluminescence Pre-dose Dating of Ancient Porcelains

Thermoluminescence dating is an important means to identify the authenticity and dating of ancient ceramics, while the sum of the environmental background radiation energy received by the porcelain after high-temperature firing can be judged by measuring the photon energy released by porcelain, so as to estimate the time elapsed from high-temperature firing to the present. However, if the porcelain is subjected to a high temperature event during preservation, the thermoluminescence energy accumulated by the crystals inside the porcelain will be released in whole or in part, resulting in an age that may not be the actual one of the porcelain. In this study, ancient porcelain samples were subjected to heat treatment at different temperatures, while the cumulative radiation dose was measured by using thermoluminescence pre-dose technology to explore the effect of heating temperature on the results of thermoluminescence dating. It is showed that heating temperature below 300 ℃ had no significant effect on the dating results. When the temperature exceeded 400 ℃, the dating results decreased with increasing temperature. When the temperature was higher than 600 ℃, the thermoluminescence signal disappears completely. Therefore, in order to ensure the accuracy of thermoluminescence dating, it is necessary to understand the heating history of ancient porcelain in detail. When the background level (S₀) of the sample is abnormally high, it should be considered whether the sample has experienced an excessively high temperature event. If heat treatment is required during the preservation and restoration of ancient porcelain, the temperature should be strictly controlled below 300 ℃ to avoid interference with the thermoluminescence signal. This discovery has important practical guiding significance for the identification and protection of ancient porcelain.