What is the ILC?

The International Linear Collider (ILC) is a next-generation linear accelerator, and its design and development are being promoted through international cooperation.

The ILC is expected to become an international research center that will continue its research for 10 to 20 years, with thousands of world-class researchers and engineers from more than 1,000 universities and research institutions, and 100 countries around the world all gathering in the Kitakami Mountains in Tohoku.

The Structure of the ILC

In a straight underground tunnel with a total length of several tens of kilometers (current plan is approximately 110 m above sea level and about 20 km in total length), electrons and positrons (* 1) are accelerated to a speed close to the speed of light and are collided head-on.

This will create a state similar to one pico-second after the birth of the universe.

A situation similar to what existed immediately after the Big Bang (* 2) will be reproduced instantaneously, and various particles including the Higgs boson (* 3), a particle that affects mass, will appear.

By observing these particles, we will attempt to unravel mysteries that have puzzled humanity for hundreds of years: How did the universe come into existence? How was matter created?

In addition, accelerator technology can be applied to a wide variety of fields, including healthcare and biotechnology, the extraction of new materials, information and communication, measurement, the environment and energy.

The Conditions for ILC Construction Site

In addition to being host to the linear accelerator tunnel (with a maximum length of 50 km), the site would also need access tunnels as well as a large underground hall that would accommodate particle measuring instruments.

Moreover, collisions between electrons and positrons need to be precise, so it is required to be able to construct a tunnel within hard stable bedrock with little artificial vibration and no active faults.

If the ILC is constructed

If the ILC is realized, a multicultural, international city will be created in Tohoku, home to thousands of researchers and their families from all over the world.

By creating an international “hub of knowledge”, it is hoped that the young people in the area, having seen leading-edge research up close, will have a new thirst for knowledge and create new hopes and goals.


※1 Positron・・・・・・・・・The opposite (antiparticle) of an electron.

A positron has a positive charge, in opposition to the electron’s negative charge.

※2 Big Bang・・・・・The giant explosion that is said to have occurred at the beginning of the universe.

According to the Big Bang theory, the universe started approximately 13.8 billion years ago with an explosion (the Big Bang), and as the universe expanded, elementary particles, atoms, molecules, stars, and galaxies were created.

※3 Higgs Boson Particle・・・・In the same way that water fills the ocean, the universe is filled with Higgs boson particles, and it is believed that they are what give elementary particles mass. 
Immediately after the Big Bang, the elementary particles had no mass, but as the universe expanded and began to cool, an ocean of the Higgs field was formed. The elementary particles encountered resistance from this ocean, and it is thought that this difficulty in moving may have led to mass.