Thermoluminescence dating definition

16-Jan-2020 20:40

These crystalline solids are constantly subjected to ionizing radiation from their environment, which causes some energized electrons to become trapped in defects in the molecular crystal structure.An input of energy, such as heat, is required to free these trapped electrons.A sampling of topics: a brief history of dosimetry, calibration protocols, and the need for accuracy; cavity theory, stopping-power ratios, and correction factors; ionization chamber instrumentation; review of TG-51 protocol; kilovoltage x-ray dosimetry; clinical electron beam dosimetry, detector and Monte Carlo techniques for reference-quality brachytherapy dosimetry; dosimetry for small photo beams used for stereotactic radiosurgery/radiotherapy; hadron dosimetry; radiochronic film; diamond detector; gel dosimetry; Fricke and alanine dosimeters; and stopping-power ratios, rations of mass-energy coefficients, and CSDA ranges of electrons.

This is commonly done by measurement of the alpha radioactivity (the uranium and thorium content) and the potassium content (K-40 is a beta and gamma emitter) of the sample material.

Thermoluminescence Dating Thermoluminescence can be used to date materials containing crystalline minerals to a specific heating event.

This is useful for ceramics, as it determines the date of firing, as well as for lava, or even sediments that were exposed to substantial sunlight.

Most excited electrons will soon recombine with lattice ions, but some will be trapped, storing part of the energy of the radiation in the form of trapped electric charge (Figure 1).

Depending on the depth of the traps (the energy required to free an electron from them) the storage time of trapped electrons will vary - some traps are sufficiently deep to store charge for hundreds of thousands of years.

This is commonly done by measurement of the alpha radioactivity (the uranium and thorium content) and the potassium content (K-40 is a beta and gamma emitter) of the sample material.

Thermoluminescence Dating Thermoluminescence can be used to date materials containing crystalline minerals to a specific heating event.

This is useful for ceramics, as it determines the date of firing, as well as for lava, or even sediments that were exposed to substantial sunlight.

Most excited electrons will soon recombine with lattice ions, but some will be trapped, storing part of the energy of the radiation in the form of trapped electric charge (Figure 1).

Depending on the depth of the traps (the energy required to free an electron from them) the storage time of trapped electrons will vary - some traps are sufficiently deep to store charge for hundreds of thousands of years.

Natural crystalline materials contain imperfections: impurity ions, stress dislocations, and other phenomena that disturb the regularity of the electric field that holds the atoms in the crystalline lattice together.