The international linear collider

his reference report contains the technical specifications and design for an International LinearCollider that is based on mature technology and is relatively low risk. The heart of the acceleratorconsists of two approximately 11-km long SCRF main linacs, based on the technology developed bythe TESLA collaboration and proposed in 2001 for the TESLA linear collider [5]. The updated designreflects the significant worldwide developments in this technology, with the establishment of R& Dinfrastructure as well as a significant industrial base in the Americas, Asia and Europe. The globalhigh-gradient SCRF R& D driven by the GDE has succeeded in routinely establishing the required35 MV/maverage performance, with every indication that this could be exceeded in future years. Integrated systems tests at the TTF2/FLASH accelerator in DESY, Hamburg have demonstratedmany of the design and performance parameters for the ILC, and this currently unique facility willsoon be joined by similar test accelerators in both KEK, Japan, and Fermilab, USA.