The trapped electrons form para-magnetic centers and give rise to certain signals that can be detected under an ESR spectrometry.
Electron spin resonance dating can be described as trapped charge dating.
Radioactivity causes negatively charged electrons to move from a ground state, the valence band, to a higher energy level at the conduction band.
ESR dating in archaeology has been applied to tooth enamel, speleothems, spring deposited travertines, shells and burnt flint.
These applications are described in detail and examples are given to illustrate the contribution of ESR dating to the establishment of archaeological chronologies.
The dose rate is found from the summation of the concentrations of radioactive materials in the sample (internal dose rate) and its surrounding environment (external dose rate).
The dosages of internal and external radioactivity must be calculated separately because of the varying differences between the two.
ESR dating has been systematically applied in earth sciences and archaeology since 1975 when Ikeya dated a stalactite from the Akiyoshi cave in Japan.
In the meantime this new technique has been successfully applied to the dating of materials such as speleothems, spring deposited travertines, mollusc shells, corals, and tooth enamel.
Trapped electrons only have a limited time frame when they are within the intermediate energy level stages.
After a certain time range, or temperature fluctuations, trapped electrons will return to their energy states and recombine with holes.
After a short time, electrons eventually recombine with the positively charged holes left in the valence band.