On December 19, the Science Council of Japan which had been examining significance reached the conclusion that the proposed construction plan of “International Linear Collider (ILC)” of huge accelerator over the Kitakami Kochi (highland) located between Iwate and Miyagi prefectures is not worth supporting the invitation.

The Government seems to follow the council’s conclusion for the coming deadline of decision in March 2019, and the long-discussed invitation of ILC into Japan is so likely to have no way but giving up.

Regarding the assumed bearing of the main part of construction cost amounting to 800 billion yen which might possibly be imposed to Japan, the Science Council of Japan pointed out as follows:
1. It seems to be far from measuring up to an expected scientific accomplishment.
2. The economic merit and technical diffusion effects are quite opaque and limited.
3. The international cost sharing plan and measures to procure necessary human resources are ambiguous.

The ILC is a huge accelerator to produce Higgs bosons by collision of electrons with positrons under an ultra-high energy in the linear tunnel 20 km long (shorter than before) provided 100 meter underground, and it employs a superconducting cavity for acceleration. It is aimed to investigate in detail the Higgs boson generated by a Big Ban having the biggest feature to realize a direct observation of all reactions of elementary particles.

As the superconducting cavity for acceleration is used at an absolute temperature close to zero degree, its accelerator is stored in a cryostat and the surrounding area is filled with liquid helium. In addition, as the evaporated liquid helium is liquefied back, a helium liquefying system is required. Taiyo Nippon Sanso supplied an ILC testing bench of 250ℓ per hour to the High Energy Accelerator Research Organization in 2013.