At its recent meeting in Japan, the International Committee for Future Accelerators (ICFA) decided that it would form a small subcommittee to discuss and recommend what structures should follow the current Linear Collider Board (LCB) and Linear Collider Collaboration (LCC) when their current (extended) mandates terminate at the end of this year. The committee consists of the leaders of experimental particle physics: the Chair of ICFA and DESY’s director for particle and astroparticle physics, Joachim Mnich, the Director-General of CERN, Fabiola Gianotti, the Director of Fermilab, Nigel Lockyer and the Director-General of KEK, Masanori Yamauchi. As they muse on the future for our linear collider activities, I am taking this opportunity, as an outgoing Regional Director of LCC, to give them some unsolicited advice!
One of the comments I made in the discussion at the ICFA meeting was that the roles of those leading the successor organisation to LCC – let me call it LCC’ – should be capable of being achieved. This may sound obvious but, to be honest, some of the current roles in LCC cannot be successfully carried out. For example, my own, which is substantially involved in discussions with European political and funding authorities and the European Union, cannot succeed in the absence of some sort of signal that there is a host that would like to explore the possibility of setting up a world-wide collaboration to build the International Linear Collider (ILC). As we have heard recently, this is unlikely to be forthcoming from Japan before 2018. Thus I would recommend that LCC’ should not have Regional Directors, but instead have contact persons, perhaps in each of the major countries likely to want to contribute to ILC construction. These contact persons could maintain links with their funding authorities and be ready to spring into action if and when a “green light” is given to initiate concrete discussions.
The main function of LCC’, it seems to me, is to maintain the Compact Linear Collider (CLIC) and ILC collaborations in healthy and working order until a concrete decision on either CLIC or ILC construction is given. This is not a trivial job. Let me concentrate on the ILC: it seems clear to me that the R&D for CLIC should continue more or less along the current lines until the next European Strategy discussion. The LCC has I think done remarkably well, with minimal resources, in maintaining a team of experts, almost all of whom are part time, working on refinement of the ILC design. As has been said many times before in these pages, the ILC is a mature technology, whose “10% prototype” (!), the European XFEL at DESY, is almost complete. Nevertheless, there is much optimisation and site-specific design that remains to be done and it has continued under the LCC with significant and, at least to me, surprising success. Nevertheless, there is a limit to the patience, availability and even longevity of the necessary experts that the current timescale of ILC is pushing to its extreme. Thus the job of LCC’, in a period where it seems highly unlikely that resources can increase or even be maintained, will be very challenging indeed. From these considerations it is clear that we will continue to need Directors for the accelerator activity. I would recommend that LCC’ should have an overall Director, with three Associate Directors, one for the CLIC machine, one for ILC machine and one, as now, for physics and detectors. Together with the national contact persons, I think this makes a team which has a chance of fulfilling the necessary goals.
As for the LCB, I don’t see any particular reason to change the current setup. The suggestion when the LCB was set up was that it should be more “executive” than its predecessor and more active in political activities. Again, however, this does not seem possible without a green or at least an amber light from a host country. We should return to a chair that rotates around the three regions, perhaps with a two-year term.
So ends my unsolicited advice to my senior colleagues. It is essential that we maintain our linear collider collaboration in being for as long as is necessary for the funding and political authorities to come to a decision. Those of us who have been involved for decades have demonstrated our commitment and patience. Difficult though it may be, it is essential that we continue until what will hopefully be a positive decision to finally realise our linear collider dreams.