Report from the CLIC-ILC General Issues Working Group

1. Report from theCLIC-ILC General Issues Working Group Mike Harrison PAC Meeting, Prague Nov 14/15, 2011

2. The General Issues Working Group EckhardElsen – DESY Mike Harrison - BNL Philippe LeBrun – CERN Ken Peach – Oxford Daniel Schulte – CERN Kaoru Yokoya - KEK We report to the ILCSC and the CLIC Collaboration Board. Status updates to this group. The first report was issued last January, the second will be released this January, and the final report by 2012 year end. The first report was presented to the PAC at the last meeting in Taipei.

3. Interim Report #2 • Siting • We looked at the technical issues regarding siting and there is not much of consequence, but what there is involves CLIC: the footprint is a bit more complicated due to the drive beam system, vibration specs could rule out some sites but not most, cultural noise would suggest a deep site which must be laser straight. • Industrial Procurement: experience from the LHC • Component numbers for SRF larger than the LHC – big enough for automation ? • LHC was CERN based thus subject to CERN procurement practices – ILC world based • How to value in-kind contributions when the same component costs vary globally • Should have the “right” level of technology in the technical designs to allow industrial production where possible. • Single or multiple sourcing ? LHC generally chose multiple. Single sourcing was either a success or a failure. • Intermediate component supply: critical components were CERN supplied but this complicates logistics • Build-to-print for “CERN owned “ technology otherwise functional and interface specs

4. Interim Report #2 • Industrial Procurement: experience from the LHC (continued) • Risk should be taken by the most knowledgeable party • Operating costs (10 years) were taken into account e.g. efficient cryo plants • The industrial “jungle”: quality drift, supply chain failure, organizational changes, strikes, bankruptcies ….. Bound to happen on a long project. • Decision Process: how to integrate LHC results into the linear collider program • Higgs or no Higgs ? • SUSY or no SUSY ? • Standard model or beyond the standard model ? • We will have the results from the present LHC run then nothing new until 2015/16. We need some form of community review in 2013 to arrive at an LC consensus. • An Assessment of the Technical Working Groups • Not subject to much day-to-day management from the project • Largely autonomous in regard to technical topics & organization • While cross-over activities certainly exist and there are common goals in the test facilities,most work is still project specific • Value added comes from comparing results, critiquing designs, developing concepts … • How should the WG’s evolve ?

5. Final report • Issues part of project implementation plans • Siting • criteria and constraints • CLIC specificities • Preparation of technical procurement • Considerations of mass producing hi-tech components • QA, industrial follow-up • Decision point(s) for the LC • Points of comparison between the two approaches • Physics reach • Maximum energy: in relation to first LHC results • Energy staging and upgradeability • Luminosity (incl energy spread & background) & polarization • Lower-energy operation, energy fine scans • Accelerator technology • Explore (& compare ?) strength/weaknesses of the two approaches • Comparative reliability • Future technology development? • Cost & power estimates • Topical joint WGs • Follow-up of existing ones • Possible new topics: • RF power sources • Surface cleanliness in an industrial production • Beam instrumentation • Conclusions 2nd Interim Report Final Report 2nd Interim Report

6. Final report (since this work has not really started the next few slides are largely my own personal prejudices ) • Physics reach • Maximum energy: in relation to first LHC results • Can we say anything here ? Can we frame the discussion ? • Energy staging and upgradeability • Make longer is the zeroth order solution. BDS issues for 500 Gev -> 3 Tev • Luminosity (incl energy spread & background) & polarisation • 20 mrad v’s 14 mrad • Lower-energy operation, energy fine scans

7. Final report • Accelerator technology • Explore (& compare ?) strength/weaknesses of the two approaches • Here we have asked the technical working groups for their opinions on what they consider to be the critical issues in their design areas. The GI WG will evaluate their responses as well as our own opinions. • Comparative reliability • I suspect that only an analysis at the – better, worse, same – level is sensible at this point. Not much information on ILC, none on CLIC, at the system level. • Future technology development ? • ILC : higher gradients, 2.6 GHz (in the context of energy upgrades), positron production & polarisation • CLIC: higher gradients but the baseline itself is a challenge in the near term • Both: value engineering

8. Final report • Cost & power estimates • Will this be the ‘official’ cost comparison ? • We will probably pick up the cost v’s energy recommendation from our first report i.e. base cost (Zero energy collider) + cost per Gev • CLIC costs in April, ILC costs in ? • What is the relative accuracy/maturity of the cost estimates ? • A linear collider is single pass thus wall plug power (for a given technology) is determined to first order by the beam energy and current. • The RDR estimated 214 MW (82 base + 132) for 500 Gev. Nick recently estimated an additional 100 MW for a 1 Tev ILC with a somewhat more energy efficient parameter set. • J-P D gave a CLIC estimate in Eugene of ~650 MW for a 3 Tev machine. Is it reasonable to propose a facility that is this power hungry ? If not then is the CoM energy set not by physics or technology but energy consumption. • There seems to be no large difference in power consumption between either approach • Can the energy efficiency be improved for SRF or 2-beam LC designs ?