The International Linear Collider (ILC) is a proposed linear particle accelerator. It is planned to have a collision energy of 500 GeV initially, with the possibility for a later upgrade to 1000 GeV (1 TeV). The host country for the accelerator has not yet been chosen and proposed locations are Japan, Europe (CERN) and the USA (Fermilab). Japan is considered the most likely candidate, as the Japanese government is willing to contribute half of the costs, according to a representative for the European Commission on Future Accelerators. Construction could begin in 2015 or 2016 and will not be completed before 2026.
Studies for an alternative project called CLIC the Compact Linear Collider are also underway, which would operate at higher energies (up to 3 TeV) in a machine with comparable length as the ILC.
The ILC would collide electrons with positrons. It will be between 30 km and 50 km (19–31 mi.) long, more than 10 times as long as the 50 GeV Stanford Linear Accelerator, the longest existing linear particle accelerator. The proposal is based on previous similar proposals from Europe, the U.S., and Japan.
Read more about International Linear Collider: Comparison With LHC, ILC Physics and Detectors, Merging of Regional Proposals Into A Worldwide Project, Design, Proposed Sites, Cost and Time Estimates