Linear Breit-Wheeler pair production by high-energy bremsstrahlung photons colliding with an intense x-ray laser pulse

A possible setup for the experimental verification of linear Breit-Wheeler pair creation electrons and positrons in photon-photon collisions is studied theoretically. It combines highly energetic bremsstrahlung photons, which are assumed to be generated by an incident beam GeV penetrating through a high-$Z$ target, with keV photons from x-ray laser field, described as focused Gaussian pulse. We discuss dependencies yields on electron energy, target thickness, parameters, collision geometry. shown that, suitable conditions that nowadays reach at facilities, resulting number created particles seems well accessible enabling first observation process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}$.