ROSE: A numerical tool for the study of scattering events between photons and charged particles

We present the dimensioning of a photon-photon collider based on conventional Compton gamma sources for the observation of secondary γγ production. Two symmetric electron beams in collision with two high energy lasers produce two primary gamma rays pulses through Compton back scattering. Tuning the energy of the system to the energy of the photon-photon cross section maximum, a flux of secondary gamma photons is generated. The Monte Carlo code 'Rate Of Scattering Events' (ROSE) has been developed adhoc for the counting of the QED events. The benchmark of the code for the Compton scattering process is presented. Realistic numbers of the secondary gamma yield, referring to existing or approved set-ups are presented.