Interaction region for gamma-gamma, gamma-electron collisions at linear   colliders
  Photon colliders (gamma-gamma, gamma-electron) are based on backward Compton scattering of laser light off the high energy electrons in linear colliders. All projects of linear colliders include this option. In this paper physics motivation, possible parameters and some interaction region aspects of photon colliders are discussed. 
Valery Telnov (Institute of Nuclear Physics, Novosibirsk)