Thermolumineszenzdatierung

Thermoluminescence (TL) is a form of luminescence that an irradiated material emits when it is subsequently heated. The light arises from recombination of charge carriers that were trapped in defects within the crystal lattice after exposure to ionizing radiation. Heating provides energy to release these trapped electrons, which recombine at luminescent centers and emit photons. The emitted light intensity is related to the amount of radiation absorbed since the last heating event.

TL has important applications in dating and dosimetry. Thermoluminescence dating uses the accumulated radiation dose stored in a material since it was last heated or exposed to strong light, such as pottery, burnt flint, or sediment grains. By measuring the equivalent dose and dividing by the environmental (annual) dose rate, researchers estimate the time elapsed since the last heating. TL dating is commonly used in archaeology, geology, and sedimentology and is complementary to other methods such as radiocarbon dating and optically stimulated luminescence (OSL).

Measurement involves heating a prepared sample in a TL reader to produce a glow curve—the emitted light as a function of temperature. The glow curve is analyzed to determine the absorbed dose and to identify different trap populations. Calibration with known doses, control of environmental factors (notably moisture), and careful sample preparation are essential. In dosimetry, TL can be used to measure cumulative radiation exposure in materials and dosimeters.

Common TL materials include quartz and feldspar minerals, pottery, and certain phosphors. While powerful, TL dating and dosimetry require careful interpretation due to factors like partial bleaching, thermal history, and varying dose rates.