The purpose of this study was to observe the
energy distribution of incident 511-keV photons
produced as a result of annihilation effect e-+e+
γ+γ in
three different electrodes (of aluminum, glass, and
Bakelite). The transmission, absorption, and reflection of
particles for 511-keV photons were examined using a
thin or thick layer of electrodes. Moreover, the manner
in which the energy spectrum of a single electrode
changes with its thickness was explored. The positron
range of the positron emission tomography (PET)
radioisotopes is responsible for the production of highquality images in (PET) imaging reconstruction. As a
result, the ranges and kinetic energies of positrons from
three radioisotopes (F18, O15, I124) were calculated in this
study using the Geant4 application for tomographic
emission (GATE) simulation package. Notably, the
ranges thereof were determined via their
energies.Finally, the simulated ranges and kinetic energy
values were compared with the literature values
revealing a 0.5% difference
Keywords : Annihilation effect, Positron Emission Tomography (PET), Imaging reconstruction, Radioisotopes.