Investigation of QED Effects With Varying Z in Thin Foil Targets

Quantum electrodynamics (QED) effects in intense laser-plasma interaction were investigated using particle-in-cell (PIC) simulations, specifically the generation of electron-positron pairs. Linearly polarized intense laser pulses were used to irradiate a thin foil (1-μm) with an intensity of 4 x 10
²³
W cm
^-2
. A scan of targets with varying Z (Al, Cu, and Au) is investigated to determine the effect of target Z /density on electron-positron pair production. The total number of pairs created for Al and Cu targets is 10
¹⁴
and 10
¹³
, respectively. In the case of Au, we did not observe any pair production to occur. We have also calculated the variation in electron energy in these targets. The results indicate that target Z plays a very important role with the laser interaction in the pair production process, which will be explained in this article.