A conception of the photon collider beam dump
  Photon beams at photon colliders are very narrow, powerful and can not be deflected. For the beam dump at the TESLA-like collider we suggest to use a long gas (Ar) spoiler in front of the water absorber, this solves the overheating and mechanical stress problems. The neutron background at the interaction point is estimated. 
L.I. Shekhtman, V.I. Telnov (Institute of Nuclear Physics,   Novosibirsk, Russia)