Mahshid Zare; Behjat Ghasemi; Omid Reza Kakuee; Ali Biganeh
Abstract
The potential biomedical application of Positron Annihilation Spectroscopy (PAS) for nonstructural characterization of normal and cancer cells was not thoroughly employed and researched. In this paper, the experimental investigation of the oxygen sensing ability of the PAS technique for tumor imaging ...
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The potential biomedical application of Positron Annihilation Spectroscopy (PAS) for nonstructural characterization of normal and cancer cells was not thoroughly employed and researched. In this paper, the experimental investigation of the oxygen sensing ability of the PAS technique for tumor imaging is presented and discussed. This research is based on the validated hypothesis that tumor cells differ from the normal tissues in their value of oxygen concentrations. The components of Doppler Broadening and positron annihilation lifetime spectra are measured with our homemade spectrometer to determine the mechanism behind the positron annihilation in oxygen content tissue-equivalent samples. The analysis of PAS data shows that the Orbital Momentum Spectrum (OEMS) of the Coincidence Doppler Broadening Spectroscopy (CDBS) and the positronium lifetime components of Positron Annihilation Lifetime Spectroscopy (PALS) are sensitive to the presence of oxygen. The results are applicable in the development of a tumor imaging system based on the PAS technique.
Ali Biganeh; Hosein Rafi-Kheiri; Omidreza Kakuee
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) ...
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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.
