For the planned International Linear Collider it is intended to have both --- electron and positron --- beams polarised. This offers a great benefit for many physics studies, but also provides a challenge for the engineering of the machine. A polarised positron source that meets the machine parameters is topic of current design studies and prototype experiments.

PACS numbers: 13.66.--a, 13.88.+e, 29.27.Hj, 24.10.Lx