An international journal published by K. N. Toosi University of Technology

Document Type : Research Article

Authors

Physics and Accelerators Research School, Nuclear Science and Technology Research Institute, P. O. Box 14395-836, Tehran, Iran

Abstract

A two-dimensional coincidence technique is carried out to suppress the background for exploring the contribution of positron annihilation with core electrons. The spectrometer is composed of two face-to-face HPGe detectors. To test the performance of the system, the Coincidence Doppler Broadening (CDB) ratio curve of pure well-annealed Copper is investigated. The quality of the annealing process is measured using Positron Annihilation Lifetime Spectroscopy (PALS). For comparison of the ratio curve of different laboratories, an Aluminum sample is considered as a reference due to its simple electronic structure. The element-specific CDBS signature of Copper shows the two peaks around 12.8×10-3 m0c and 19×10-3 m0c at the ratio curve which is dependent on the momentum of Fermi electrons. The presented ratio curve is compared with the reference measurement and simulation. Differences and the similarities in the reported ratio curves are discussed. The comparison shows that our result is more compatible with the theoretical calculations and can be considered as a new reference for future studies on the chemical environment of defects in alloys that include Copper in their contents.

Highlights

  • The detailed shape of the CDB-ratio curve is a speci c signature of each element.
  • The CDBS ratio curve of well-annealed copper is measured and compared with simulation.
  • The annealing quality of the copper is evaluated using the PALS technique.
  • The element-speci c CDBS signature of the Copper shows two peaks at the ratio curve.
  • The ratio curve depends on the spectrometer energy resolution and the peak to Compton ratio.

Keywords

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