Development of a pulsed, variable-energy positron beam for atomic scale defect studies

A C L Jones; R G Greaves; C L Codding; F A Selim

doi:10.1063/5.0077750

Development of a pulsed, variable-energy positron beam for atomic scale defect studies

Rev Sci Instrum. 2022 Apr 1;93(4):043903. doi: 10.1063/5.0077750.

Authors

A C L Jones¹, R G Greaves², C L Codding³, F A Selim¹

Affiliations

¹ Department of Physics and Astronomy, Bowling Green State University, Bowling Green, Ohio 43402, USA.
² Department of Physics and Astronomy, University of California Riverside, Riverside, California, 92507, USA.
³ Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43402, USA.

PMID: 35489933
DOI: 10.1063/5.0077750

Abstract

Positron annihilation spectroscopy provides a sensitive means of non-destructive characterization of materials, capable of probing single atom vacancies in solids with 10^-7 sensitivity. We detail here the development of a magnetically guided, variable energy, pulsed positron beam designed to conduct depth-dependent defect studies in metals, semiconductors, and dielectrics, which will be the first of its kind in the United States. The design of the target stage provides capabilities for measurements during in situ annealing up to 800 °C and incorporates a new approach to minimize the background due to energetic backscattered positrons. The developed beam at Bowling Green State University provides a powerful tool for characterization of thin films, devices, and ion irradiated materials.