A cryomodule, a key component of the proposed International Linear Collider

© Rey.Hori/KEK

Japanese government punts on decision to host the International Linear Collider

The government of Japan finally said something about hosting the International Linear Collider (ILC): It still can’t make up its mind, and it may hold off on a decision until the fall, if not longer.

This morning in Tokyo, an official of Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT) explained to a meeting of the International Committee for Future Accelerators (ICFA) and the Linear Collider Board that the ministry could “not yet” indicate the intention of “hosting the ILC in Japan,” according to a written executive summary of the presentation obtained by ScienceInsider. “MEXT will continue to discuss the ILC project with other governments while having an interest in the ILC project,” the summary concludes. 

“There was disappointment” among the scientists at the meeting, ICFA chair Geoffrey Taylor, an experimental physicist at the University of Melbourne in Australia admitted at a briefing this evening in Tokyo. “People were hoping there would be a statement that Japan was willing to host the ILC.”

Japanese physicists in particular were hoping for positive news. In December 2018, the influential Science Council of Japan (SCJ) concluded in a report that it could not “reach a consensus to support hosting” the project, citing concerns over Japan’s share of the cost of the $7.5 billion machine and unresolved technical issues. Since then, regional politicians, industrial lobbyists, civic groups, and chambers of commerce have argued in favor of hosting the collider, which they hope will stimulate economic development in the region hit by the 2011 earthquake and tsunami.

The ILC is designed to produce Higgs bosons in sufficient quantities to determine the properties of the elusive particle, experimentally confirmed in 2012. “Having a Higgs factory is the No. 1 idea in particle physics right now,” Taylor explained. Japan had emerged as the leading contender to host the ILC after preliminary cost estimates scared off other countries.

Taylor tried to put a positive spin on the situation, noting that “this is not a dead end.” In a letter presented to the Linear Collider Board, Keisuke Isogai, director-general of MEXT’s research promotion bureau in Tokyo, explained that a commitment might still be possible if the ILC gains “understanding and support from the domestic academic community,” particularly in the context of a “Master Plan of Large Research Projects” now being considered by SCJ. Given the council’s skepticism about the project, “We will show them that we already have solutions for the technical challenges and we are going to start making a framework for international cost-sharing,” said Masanori Yamauchi, director-general of KEK, Japan’s high energy research center in Tsukuba.

A draft of the master plan is due in the fall, with a final recommendation from SCJ coming in about a year. “We’re still very hopeful that in not too long a time we will end up with a positive response to hosting the ILC” from Japan, Taylor said, though he noted that further delays could diminish the importance of the ILC given nascent competing proposals for other Higgs factories.