[en] The detection of two gamma photons in time coincidence is the main process in Positron Emission Tomography. The front end processor estimate the energy and the time stamp of each incident gamma photon, the accuracy of such estimation improves the quality of contrast and resolution of final images. In this work a modeling tool of the full detection chain is described. Starting from stochastic generation of light photons, followed by photoelectrons time transit spread inside the photomultiplier, preamplifier response and digitalisation process were modeling and finally, several algorithms of Energy and Time Stamp estimation were evaluated and compared. (author)