Investigating laser-driven pair-production with a fast, end-to-end, analytical model

Laser-driven positron sources, generated through ultra-intense laser–matter interactions, have attracted significant interest due to their relevance in fundamental physics, laboratory astrophysics, and advanced applications. However, their modeling remains challenging, as the generation of electron–positron pairs involves a complex chain of strongly coupled physical processes, including preplasma formation, relativistic electron acceleration, transport, photon emission, and pair-production. Existing approaches typically rely either on simplified analytical models or on computationally intensive numerical simulations, preventing the simultaneous achievement of rapid solution times and an end-to-end description of the complete process. In this work, a fast, end-to-end, coupled analytical – scaling-law model is developed to provide a computationally efficient description of the complete pair-production process during the interaction of an ultra-intense laser with an Au target. The model integrates all major physical mechanisms and enables direct assessment of their importance. The analysis reveals a clear hierarchy among the underlying processes, with preplasma conditions playing a dominant role, while other mechanisms such as radiation yield and electron attenuation introduce secondary but non-negligible effects. Furthermore, a controlled preplasma case study demonstrates that tailoring preplasma properties can enhance number of positrons by several orders of magnitude, particularly for sub-petawatt laser systems, while improvements become limited in the petawatt regime due to saturation of the Bethe–Heitler process. The proposed model provides a rapid, end-to-end tool for interpreting experiments and exploring optimization strategies, offering a comprehensive framework for the development of next-generation laser-driven positron sources.