Discussion of ILC at OSTP – Paul Grannis, Sept. 13, 2005
I want today to give you some background briefing on the International Linear Collider project: the scientific arguments that are formulated to justify it, the recent steps to organize it and to prepare a firm design for costing, and the funding needs for the next several years. Let me be brief since there is much of this you probably know, to leave time to explore the issues that you wish.
I prepared several handouts (intended to mix and match elements for different audiences) on an overview of the ILC project, the scientific questions it will address, the accelerator project itself, societal impacts, and the steps toward organizing the project.
The physics case for the ILC is exceptionally strong. The ILC will address basic questions about the construction of matter, the nature of dark matter and the early moments of the universe, the unification of forces and the possibility of extra dimensions of space. Advisory committees in Europe, Asia and the US have placed the ILC as the top priority for the next worldwide project; the OECD ministers noted this consensus “as the next accelerator-based facility to complement and expand on the discoveries … from the LHC”. Nearly 3000 physicists worldwide signed a document supporting the priority of the physics goals. Ray Orbach put the ILC as the top priority for the intermediate-term Office of Science facilities.
The scientific questions can be set in the context of the Quantum Universe report; nine questions are posed there as the overarching themes for investigation in the next decade or two. The ILC would address at least eight of these.
The scientific argument rests on the success of the Standard Model in defining the nature of matter and energy at the sub-Terascale scale; we know with confidence that the SM becomes incomplete at the Terascale and that new physical phenomena will emerge there. The certainty that there is new physics does not translate into understanding what it is; for that experiments are needed to show us Nature’s way.
The ILC and LHC will operate in a close and symbiotic relationship. The LHC will see evidence for the new physics, but in many cases cannot home in on the details sufficiently to define its character. The ILC with its precisely determined (tuneable) initial state energy, quantum numbers and polarizations gives the possibility for the precision measurements to bring this characterization. The recent HEPAP subpanel report “Discovering the Quantum Universe” outlines how both accelerators are needed to understand the Terascale. This report has a very useful (according to the EPP2010 NAS panel) table of “If the LHC discovers” then “The ILC can do” scenarios.
Let me not touch on the technical description and challenges posed by the ILC; there is a brief overview in the notes. The prototype proofs of principle for all subsystems have now been demonstrated. The current phase is R&D aimed at reducing cost, decreasing risk, and moving large systems toward industrialization.
Let me also not dwell on the broader impacts of the ILC on society. You are much better at formulating this than I am. I do note that in my view a part of the justification must be that the questions that ILC will grapple with are of basic interest to humans, and that a decision must be made in part on a desire to answer these. There will be spin-off societal benefits if history is a guide but it is very difficult to gauge these with any accuracy. It is somewhat easier to see the impact on other sciences – structural biology, environmental science, materials science, plasma physics through development of the next generation of light source technologies, nuclear and astrophysics through both the physics insights and the tools for future developments, and quite likely on medical diagnostics and treatment techniques using compact electron accelerators. All of science is indeed interconnected, in ways that are hard to forecast but through which major new steps are enabled. Each of the essential pillars of science requires sustenance.
One aspect of the justification for frontier research in high energy physics in general is its role in training new generations of scientists and engineers. HEP, like all the physical sciences, trains young people to attack problems that have no known solution and gives them general tools to bring to bear on new problems. HEP, more than most areas of physical science, deals with large overarching questions of the type that serve as magnets for drawing young people into science and technology. For many young people, the opportunity to search for more than three spatial dimensions, or solve the riddle of why there is no antimatter in the universe, is more powerful hook for entering STEM professions than more specific goals as “how can we develop smaller, less power-consuming digital circuits?” or “how can we explain high Tc superconductivity?”
The final point I want to make concerns the progress made recently toward the ILC, and the prospect for the path ahead.
I mentioned the highest priority given to ILC by high level panels in Europe, Asia and the US, and by OECD and the DOE Office of Science. The international consensus for the ILC is strong. On that springboard, a steering committee (ILCSC) was formed to guide the ILC in the phase before more formal governmental structures are set in place. In the past two years, the ILCSC has:
1. Established the scientific specifications for the ILC
2. Defined the critical R&D tasks necessary to certify each competing technology to be feasible
3. Made the decision between the two main technologies for the ILC (in favor of superconducting rf cavities)
4. Established the initial structure of the Global Design Effort (GDE) that will conduct the project prior to formal national agreements, and put in place MoUs for participating laboratories
5. Selected a director for the GDE and overseen the establishment of the GDE virtual laboratory
6. Initiated workshops with participating scientists from all regions to promulgate the ILC design.
The workshop in August 2005 in Snowmass CO brought 650 physicists to report R&D work, evaluate progress and make recommendations for the baseline configuration design of the ILC, as well as to formulate the designs of experimental detectors.
The GDE plans a three year phase of R&D to achieve a full engineering design and cost estimate:
1. Complete the baseline configuration design by Dec. 2005. To this end, 48 defining design questions were posed in Snowmass. Choices were recommended for most of these there.
2. The primary alternatives to the baseline were identified; these are primarily focused on ways that cost could be reduced or risks averted, but which were too immature to be included in the baseline at present.
3. Put the design under configuration control in Jan. 2006 so that the ILC is well defined at any time. A configuration control board will review proposals to modify the baseline so that maturing R&D results can be incorporated.
4. During 2006, complete the Reference Design Report – a full conceptual design based upon a handful of sample sites for construction. The reference design will be accompanied by a cost estimate with errors, within which the project will be expected to be constructed.
5. A full technical engineering design with understanding of the industrialization of components, specific site impact and full cost estimate will be prepared during 2007 – 2008.
6. R&D on new subsystems will continue through the Reference and Technical design phases, so that at the time of construction one can take advantage of the latest R&D developments through the change control system being put in place.
A major effort for the GDE in the next year is development of the costing methodology. Senior costing experts from each region have been appointed to the GDE; their job will be to define the ILC unit (similar perhaps to the ITER value unit) that enables cost to be put in the appropriate context of each participating nation.
The GDE also includes civil engineering experts from each region whose job it is to evaluate the range of site choices and evaluate the cost impact of various geologies and environmental factors.
The Director of the Office of Science has announced the desire of the US to host the ILC at a site somewhere near Fermilab. This has been echoed in a recent speech by Secretary Bodman.
The cost of the ILC will be large, and only by effective collaboration among the nations of the three regions will it be possible to move ahead. We should wait for the Reference Design costing to get a definitive estimate, but we expect that it will be in the $6 – 12B range when contingency (US style) and escalation are accounted for. The major cost drivers are the civil construction and the long main superconducting linacs, so this is where the impact of future R&D and value engineering will be largest. Following the ITER model, it is expected that about one half of the total cost will be borne by the host country. A HEPAP panel of NSF and DOE is now considering how to rationally plan the shutdown of present facilities (Fermilab collider and SLAC B factory) to make way for the new ILC (and LHC operations) facilities.
The primary need worldwide for the next several years is for the R&D funding and support of GDE activities that are needed to provide the technical design report. This work will establish the scope of the project and will be the basis upon which partner nations can agree to set the ILC in motion. Typically the preliminary R&D costs of large projects are about 10-20% of the final project cost. A portion of the near term costs are those associated with preparing a proposal to site the ILC at some specific location. A detailed cost estimate for the full R&D phase is still being prepared, but the estimate is that the current ~$30M per year (the designated DOE ILC budget plus some funds from LDRD-type funds at the laboratories) should grow to something like $100M per year in 2010. At present, the US expenditures for ILC R&D lag behind those in Europe, and probably those in Japan. Given the priority placed on the ILC by scientists and the US government, is the key issue for the next few years is finding the necessary R&D funds to maintain the momentum.
A group comprising representatives from funding agencies of the major national players has been formed (FALC); this group has helped formulate funding needs and organizational steps. It is now grappling with the longer term R&D funding needs and the method by which common funds can be provided for the GDE activities.
Finally, the lessons to be learned from past projects – the SSC and ITER in particular – need to be understood and applied to the ILC situation. I would particularly welcome your insights on what we should learn from the SSC failure and on the pitfalls and positive aspects of the ITER story to date.
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