Electron-positron pairs and radioactive nuclei production by irradiation of high-Z target with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math> -photon flash generated by an ultra-intense laser in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>λ</mml:mi><mml:mn>3</mml:mn></mml:msup></mml:math> regime

This paper studies the interaction of laser-driven $\ensuremath{\gamma}$ photons and high-energy charged particles with high-Z targets through Monte Carlo simulations. The interacting are taken from particle-in-cell simulations a tightly focused ultra-intense laser pulse titanium target. Lead is chosen as secondary target because its high cross-section giant dipole resonance electron-positron pair production. results reveal an ultra-short, ultra-relativistic collimated positron population their energy spectra, angular distribution, temporal profile found. We investigate thickness dependence resulting total numbers kinetic energies various particle species emitted lead irradiated laser-generated separately. plot charts residual nuclides generated by irradiation Because short duration, photon, electron-positron, neutron sources could find applications in material science, nuclear physics, laboratory astrophysics, injectors laser-based accelerators particles.