KEK publishes the International Working Group's Recommendations for International Linear Collider

Tsukuba, Japan - 2 October 2019. KEK published a document on the recommendations for the International Linear Collider (ILC), a next-generation particle physics project, based on the report by the International Working Group on the ILC. The purpose of this document is to present some important aspects on implementation of the ILC project.

In May this year, KEK established the International Working Group on the ILC project to discuss issues such as international cost sharing for construction and operation, organization and governance of the ILC Laboratory, and international sharing of the remaining technical preparation.

The Working Group consisted of two members from Europe, two members from North America, and three members from Asia (including Japan). The Working Group held five meetings in a 4-month period and delivered their report to KEK, which summarized the conclusions of the Working Group. KEK then scrutinized the report and published a document entitled “Recommendations on ILC Project Implementation” containing the Working Group’s report.

Summary of Recommendations on ILC Project Implementation

The cost of the construction of the ILC accelerator complex is mainly divided into three categories, and the sharing is proposed for each category as follows. Civil engineering will be a responsibility of the Host State. Accelerator components will be provided by all Member States. Construction of conventional facilities will be managed by the ILC Laboratory, and the Host State will provide a significant part of the conventional facilities. The operational cost should be shared among Member States, and the way of sharing should be agreed upon before the construction begins.

In the main preparatory phase of the project, a preparatory laboratory (Pre-Lab) will be established based on a mutual understanding of the laboratories around the world and with the consent of their respective governmental authorities. The Pre-Lab will coordinate the preparatory tasks needed before the construction of the ILC. The Pre-Lab will also assist the inter-governmental negotiations, which are expected to take place in parallel. KEK will play a central role as the host laboratory of the Pre-Lab. After an inter-governmental agreement on the ILC, the Pre-Lab is expected to transition into a full ILC Laboratory. The ILC Laboratory will be responsible for the construction and operation of the ILC accelerator complex.

A technical preparation plan in response to reports by ILC Advisory Panel organized by Ministry of Education, Culture, Sports, Science and Technology (MEXT) and the Science Council of Japan is presented. The plan identifies technical tasks to be carried out through international collaboration. Based on current expertise present in laboratories around the world, potential partners for international cooperation are proposed.

This document presents views from scientists concerning some important aspects of implementation of the ILC project. It is hoped that it will be helpful for discussions among governments and funding authorities.

About the ILC

The Linear Collider Collaboration (LCC) is an international endeavor that brings together about 2400 scientists and engineers from more than 300 universities and laboratories in 49 countries and regions. Consisting of two linear accelerators that face each other, the ILC will accelerate and collide electrons and their anti-particles, positrons. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they collide in the detectors at the center of the machine.

At the height of operation, bunches of electrons and positrons will collide roughly 7,000 times per second at a total collision energy of 250 GeV, creating a surge of new particles that are tracked and registered in the ILC’s detectors. Each bunch will contain 20 billion electrons or positrons concentrated into an area much smaller than that of a human hair.

This means a very high rate of collisions. This high “luminosity”, when combined with the very precise interaction of two point-like colliding particles that annihilate each other, will allow the ILC to deliver a wealth of data to scientists that will allow the properties of particles, such as the Higgs boson, recently discovered at the Large Hadron Collider at CERN, to be measured precisely. It could also shed light on new areas of physics such as dark matter.

The ILC had originally been designed with a collision energy of 500 GeV. The new version of the collider makes it less costly and faster to realize.