A modified set-up to reduce background spectra in the CDBS positron spectrometer
Department of Engineering, New Modern Energy Lab., Esfarayen University of Technology, Esfarayen, Iran
Accepted: 19 November 2021
Published online: 2 December 2021
In this study, new methods of unwanted gamma-ray (γ-ray), which reduce the background of CDBS, were used. In this modified spectroscopic method, after the positron enters the sample and is annihilated by the electrons of the valence or core of the impurity atom or the defects in the crystal structure, two gamma rays are produced, which are detected by the detectors. Background spectra in CDB-spectroscopy usually cause problems in data recording due to the use of two different detectors in its structure. This background or unwanted γ-ray in CDB-spectrum causes a lot of information to be lost about how the positron interacts with the core electrons. To solve this problem, our research team has developed a new experimental CDBS set-up which in addition to reducing the number of unwanted gamma counts, has also significantly reduced the recording time of the CDB spectrum. This modified measurement method has been tested to study changes in the electron band structure in various materials such as boehmite. The results of this new spectroscopic method compared to the conventional method show a significant reduction in unwanted gamma recording and thus a significant increase in the detection of 99% of gamma due to positron annihilation with valence and core band electrons.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021