International Linear Collider makes progress in siting, R&D

Scientists and engineers met at Fermilab this week for the Americas Workshop on Linear Colliders. Photo: Reidar Hahn

This week, members of the Linear Collider Collaboration met at Fermilab to discuss the progress and future of the proposed International Linear Collider, as well as of CERN’s Compact Linear Collider, during the Americas Workshop on Linear Colliders.

At the workshop, scientists and engineers involved in the ILC discussed both their recent successes and the work still to be done to make the 18-mile-long electron-positron collider a reality.

One recent breakthrough took place at KEK. At the Japanese laboratory’s Accelerator Test Facility, scientists achieved an electron beam height of 55 nanometers at the final focus, or the point where the collision would occur. This is the smallest electron beam ever produced. It was a demonstration that the techniques scientists used to shrink the beam would be transferable to the ILC, whose aim is an electron beam height of 5 nanometers.

“The ATF at KEK is an essential element in the R&D activity toward a linear collider,” said Linear Collider Collaboration Director Lyn Evans. “The latest results give great confidence that the design parameters of a linear collider can be reached.”

That electron beam would travel through accelerator cavities — long, hollow niobium structures that look like strings of pearls. Scientists at Fermilab have made significant advancements on this front, achieving world-record quality factors. The so-called quality factor is a measure of how effectively the cavities store energy. The more efficient they are, the lower the cost of refrigeration, which is needed to keep the superconducting cavities cold.

“This workshop at Fermilab gives us the perfect opportunity to interact with the SRF community here at the lab,” said ILC Director Mike Harrison. “We take advantage of the workshop to catch up on the latest results at the lab.”

For the first time, ILC researchers actively discussed the International Linear Collider in the context of a precise, geographical home — the Kitakami mountains in the Japan’s Iwate prefecture. Site pictures and films at the workshop included actual accelerator and detector locations among hills and trees.

“This really gives a sense of reality to the project,” said Fermilab Director Nigel Lockyer. “Now the site-specific design work needed to put the ILC in that location can begin in earnest. This has been a long time coming, and we are very pleased with this step forward.”