  In the baseline design of the International Linear Collider (ILC) an
undulator-based source is foreseen for the positron source in order to match
the physics requirements. The recently chosen first energy stage with
sqrt(s)=250 GeV requires high luminosity and imposes an effort for all positron
source designs at high-energy colliders. In this paper we perform a simulation
study and adopt the new technology of plasma lenses to capture the positrons
generated by the undulator photons and to create the required high luminosity
positron beam.
