Screening effects in pair production by 10 and 15 mec2 photons.

Abstract

With a partial-wave interpolation method we calculated the positron energy spectra of pair production in the field of atoms with atomic number Z=82 for photons of energies k=10 and 15 ${\mathit{m}}_{\mathit{e}}$${\mathit{c}}^{2}$. Our results show that the screening effect is less than about 2%. Our results also indicate that the approximate treatment of screening through energy-shift screening theory becomes inadequate for photons of energy k\ensuremath{\gtrsim}10${\mathit{m}}_{\mathit{e}}$${\mathit{c}}^{2}$.