  The radiation damage of the positron source target for the International
Linear Collider (ILC) has been studied. The displacement damage in target
material due to multi-MeV photons has been calculated by combining FLUKA
simulations for secondary particle production, SPECTER data for neutron
displacement cross-sections and the Lindhard model for estimations of
displacement damage by ions. The radiation damage of a stationary Ti6Al4V
target in units of displacements per atom (dpa) has been estimated for photons
from an undulator with strength 0.92 and period 1.15 cm. The calculated damage
is 7 dpa. Approximately 12.5% of displacement damage result from neutrons.
