An Overview of the International Linear Collider

The International Linear Collider, also known as the ILC, is a linear particle accelerator slated to be built in the late 2010s. It will publish its Technical Design Report in 2012.

The host country for the ILC has not yet been chosen, and it is currently competing for funding with the CLIC (Compact Linear Collider). The CLIC has a potential to be significantly higher-energy (1 TeV versus 3-5 TeV) and is contained in a shorter machine.

The ILC, like the Large Hadron Collider, will collide electrons with positrons. It will be between 30 and 50 km in size.

The advantage of liner particle accelerators over circular particle accelerators, like the LHC, is that a particle traveling along a bent path produces a type of electromagnetic radiation known as sychotron radiation.

The energy loss is inversely proportional to the fourth power of the mass of the particle. This means that measurements are more easily made in a linear particle accelerator.

At the International Linear Collider, physicists hope to investigate supersymmetric particles, the possible source of dark matter, the number, size and shape of any TeV-scale extra dimensions, and the mass, spin, and strength of the Higgs-Boson. 

The ILC will use a 2-nanosecond laser light pulses to produce electrons. The electrons will be accelerated to 5 GeV in a 250-meter stage, and the synchotron radiation will produce positron pairs on a titanium target. The positrons will be accelerated to 5 GeV before being dampened and then sent to the main collider.

The project has changed slightly over the years. In August of 2004, the International Technology Recommendation Panel (ITRP) recommended that a superconducting radio frequency be added to the particle accelerator plans.

In 2005, the International Committee for Future Accelerators (ICFA) appointed Dr. Barry Barish as the director of the ILC global design effort.

Three sites have been proposed for the building of the International Linear Collider. These are near CERN, in Geneva, at DESY in Hamburg, and at JINR in Dubna. The preferred site at the moment is Dubna, as it is feared that CERN’s activities may interfere with the functioning of the ILC, and in Hamburg, the high water table means there is a risk of flooding any underground structure.

Outside Europe, both Japan and the United States have taken an interest in hosting the ILC. However, neither are official propositions and the interest is the subject of scientific hearsay.

The International Linear Collider is expected to cost $6.75 billion dollars, and United States secretary of Energy Steven Chu has estimated the total costs to run closer to $25 billion, though Director Barish says that this is an overestimate.