A panel of a group of scientists who want to invite the International Linear Collider to Japan have decided to promote the Kitakami area of Iwate and Miyagi prefectures as a candidate site. The particle accelerator will cost an estimated ¥830 billion, and the total including particle detection equipment and research will exceed ¥1 trillion.
Particle accelerators have helped expand the frontier of physics. But scientists and politicians who want Japan to host the ILC must present convincing reasons — including the expected economic, scientific, educational and social benefits — to the public and the government to justify the cost. At present the government and the Science Council of Japan are lukewarm about the idea.
The Large Hadron Collider at the European Organization for Nuclear Research (CERN) in the suburbs of Geneva is the largest and most powerful particle accelerator. It consists of a 27 km ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way. In 2012, the LHC helped discover Higgs boson particles. It is theorized that soon after the universe formed, Higgs boson particles filled space and clung to other weightless particles moving at the speed of light— an interaction thought to have made the latter acquire mass.
The ILC will feature a straight, 31 km tunnel. From each end, beams of electrons and positrons will be accelerated to close to the speed of light by means of a series of superconducting accelerating tubes before they are made to collide. The collision will recreate the high-energy environment that existed one-trillionth of a second after the universe was formed 13.7 billion years ago by the Big Bang. The ILC’s first task is expected to be accurate measurement and analysis of Higgs bosons. Scientists at the High Energy Accelerator Research Organization in Tsukuba, Ibaraki Prefecture, have accumulated substantial amount experience by running an accelerator that makes electrons and positrons collide.
The ILC is an enormous international project that will require time-consuming negotiations so construction won’t begin for five years. Its construction will involve the participation of some 1,000 engineers and researchers from both Japan and abroad, and take 10 years. If research and improvement are taken into account, 40 years will be needed, and there is also a plan to extend the ILC tunnel to 50 km. The project will result in the formation of a community of some 10,000 people, including scientists and their family members.
The panel expects that Japan will have to cover about half the total cost of more than ¥1 trillion, with the remaining shouldered by other countries. But the Science Council of Japan fears that Japan’s share of the expenses will reach 80 percent. Given the project’s enormous financial cost, the weak state of Japan’s economy and the soaring size of its national debt, scientists and politicians must discuss the merits and demerits of hosting the ILC in Japan in a concrete and transparent manner before any final decision is made.