Measurement principle in which the annihilation of positrons is applied to study the microscopic structure of materials.
Notes: - Annihilation lifetime (see: positron lifetime spectrometry), Doppler broadening, and the angular correlation of annihilation radiation are measured in this technique.
- In the most common case of positron annihilation, two photons are created, each with energy equal to the rest energy of the electron or positron (\(\pu{0.511 MeV} = \pu{8.187122600E-14 J}\)).
- Techniques based on PAA have been used particularly for the study polymers.
Source:
PAC, 2021, 93, 69. 'Vocabulary of radioanalytical methods (IUPAC Recommendations 2020)' on page 92 (https://doi.org/10.1515/pac-2019-0302)