Studies for a Photon Collider at the ILC
  One option at the International Linear Collider is to convert the electron beams into high energy photon beams by Compton scattering a few millimetres in front of the interaction region. Selected physics channels for this option have been analysed and technical issues have been studied. So far no showstoppers for this option have been found. 
F.Bechtel, G.Klaemke, K.Moenig, H.Nieto, H.Nowak, A.Rosca, J.Sekaric,   A.Stahl