ILC Detector R&D Reviews

1. ILC Detector R&D Reviews Chris Damerell RAL On behalf of the ILC Detector R&D Panel (a Panel of the World-Wide Study Organising Committee) (Jean-Claude Brient, Chris Damerell, Ray Frey, Dean Karlen, Wolfgang Lohmann, Hwanbae Park, Yasuhiro Sugimoto, Tohru Takeshita, Harry Weerts) LCUK - Report on Detector R&D Reviews Chris Damerell

2. Reviews of tracking (Beijing, February); calorimetry (DESY, June); vertexing (Fermilab, October); PID, muon tracking etc, (Sendai, March 2008), … • 8 external consultants for each review, supported by FALC, 3 regional representatives, RDB chair, 2-3 local experts, a few Panel members, Naomi Nagahashi and Maxine Hronek (admin support) • Tracking consultants + local experts: Peter Braun-Munzinger, Chen Yuanbo, Ioanis Giomataris, Hideki Hamagaki, Ouyang Chun, Hartmut Sadrozinski, Fabio Sauli, Helmuth Spieler, Mike Tyndel, Yoshinobu Unno • Calorimetry consultants + local experts: Marcella Diemoz, Andrey Golutvin, Kazuhiko Hara, Robert Klanner, Peter Loch, Pierre Petroff, Jim Pilcher, Daniel Pitzl, Peter Schacht, Chris Tully • Vertexing consultants + local experts: Yasuo Arai, Dave Christian, Masashi Hazumi, Stuart Kleinfelder, Simon Kwan, Gerhard Lutz, Pavel Rehak, Petra Riedler, Natalie Roe, Lenny Spiegel, Steve Watts LCUK - Report on Detector R&D Reviews Chris Damerell

3. Structure of the reviews • Collaboration reports should provide an overview of the projects through to ‘completion’ of R&D, meaning ‘ready for engineering design and construction’ • Open session presentations provide summaries of status and plans • Closed session is used to clarify technical and organisational issues, and to discuss possible needs for additional resources • Closeout session: Committee informs collaborations of the draft recommendations, and aims to reach agreement • Reports released by the WWS-OC chairs, along with optional appendices from the R&D collaborations, in which they can discuss areas of disagreement. • For tracking, see the Detector R&D Panel Wiki page http://www.linearcollider.org/wiki/doku.php?id=drdp:drdp_home • Calorimetry report will be released later this week LCUK - Report on Detector R&D Reviews Chris Damerell

4. Outcome of the tracking review • Our responsibility is to work with the R&D collaborations to ensure that the feasibility of their critical goals can be demonstrated by 2010-2012 • This means (for tracking) that the community can be confident that the option they choose will satisfy the challenging physics needs • We reviewed the LCTPC, CLUCOU, SiLC and SiD tracking R&D collaborations • We were extremely impressed by the great progress made by all these groups, in some cases with very limited resources • However, we concluded that we are currently far from the goals, for all tracking options LCUK - Report on Detector R&D Reviews Chris Damerell

5. Main technical recommendations • Building a tracking system with excellent performance for qp >7 degrees will be challenging. Feasibility is not yet demonstrated • Why not simply move on to the ‘engineering designs’ of these tracking systems and study their performance with Geant 4? • There is a risk that such designs would be too optimistic. Forward tracking has generally performed badly. We all know the solution (drastic reduction in material budget) but can this be achieved in practice? The committee concluded that this crucial question, on which a great deal of ILC physics depends, could not be answered only by adventurous designs • We became convinced of the need to construct large prototypes (~1 m diameter), and operate them under ILC-like beam conditions in a 3-5 T field, to establish what performance will be achievable at ILC, both for central and forward tracking • Until such tests are completed successfully, we do not consider that any of the three options proposed (all-silicon, TPC-plus-silicon, or drift-chamber-plus-silicon) could be considered ready for selection as an ILC tracking system [a unanimous recommendation of the committee, but not every collaboration agrees with this; maybe we are wrong] • As well, our experts made numerous detailed suggestions (see the report) which we hope are proving useful to the groups in optimising their R&D programmes LCUK - Report on Detector R&D Reviews Chris Damerell

6. A possible split-coil solenoid Estimated cost ~$800k (Elwyn Baynham industrial contacts) LCUK - Report on Detector R&D Reviews Chris Damerell

7. A new idea! • A new idea that has popped up from discussions of the tracking review committee .. • Possibility of an all-pixel tracker • Approx 50 mm square pixels, binary or 2-bit readout, ~ 30 Gpixels • Integrate signals through bunch train (backgrounds are much less than for VXD, particularly in view of ~20 mm thick sensors) • Transfer gate (until recently, available only as a proprietary feature) • CDS (correlated double sampling) readout through quiet 200 ms inter-train period, hence complete immunity to machine and other pickup during the bunch train • With ~50 ms shaping times, excellent noise with very low power (hence gas cooling) • 5-6 layers of pixels (barrels and disks) should give robust track reconstruction, even for curlers and kinks, given VXD within and ECAL beyond. ECAL will veto 2-photon and other out-of-time background • Layer thickness maybe 0.5% X0 with technologies being developed for VXD systems LCUK - Report on Detector R&D Reviews Chris Damerell

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9. SLC Experiments Workshop 1982 CCDs (not even working in a test beam) were regarded as a risky and improbable option. Workshop proceedings list many reasons why they were considered problematical LCUK - Report on Detector R&D Reviews Chris Damerell

10. What was installed 9 years later, in 1991 LCUK - Report on Detector R&D Reviews Chris Damerell

11. Outcome of the calorimetry review • Report will be published this week • A few points: • will suggest use of the MIPP facility at Fermilab to provide tagged neutrals (neutrons, anti-neutrons and KL) into the CALICE physics prototype, since the confusion term between charged and neutral hadrons drives the PFA performance, and neutral hadron showers will be different • will encourage SiDCAL to test a large-scale ECAL prototype in the CALICE setup, substituting for the CALICE physics prototype ECAL, to allow objective comparisons • Dual readout calorimeter is an interesting alternative, specially for the forward region. Much more simulation needed before moving to large-scale prototypes. DREAM collaboration needs additional support LCUK - Report on Detector R&D Reviews Chris Damerell

12. Organisational considerations • We were encouraged by the success of the task-forces that provided world-wide coordination of the ILC accelerator R&D, to wonder about the utility of Coordination Groups (VCG, TCG, CCG, …) • NOT some external body (like the Review Committee) but one or two ‘insiders’ from each R&D group, plus cross-members from related CGs • They would be free to work out their own charge, within some very general guidelines, for example as follows: • Negotiate for suitable funding for infrastructure (comprising a custom-designed test beam, solenoid, etc,), coordinate the use of these facilities, and ensure objective evaluation and presentation of the test results LCUK - Report on Detector R&D Reviews Chris Damerell

13. An important by-product: these individuals would rapidly become THE experts on every aspect of the world-wide detector R&D, and hence become a valuable source of information and wisdom for the community (like the machine taskforce leaders, Lutz Lilje, Andy Wolski, Andrei Seryi, Chris Adolphsen, … • The choice of detector technologies will as usual be made by experiment collaborations in conjunction with the IDAG or equivalent, but the CGs would aim to inform those decisions in the most objective way possible • Discussions with Sakue Yamada, Research Director for Detectors (and his directorate) will provide an opportunity to consider how best to achieve equivalent functionality for the detector community LCUK - Report on Detector R&D Reviews Chris Damerell

14. Resources • Spend on ILC detector R&D is considered by the community to be seriously inadequate (see R&D Panel Report of January 2006). Are these real needs or ‘unrestrained desires’? The first of the R&D reviews (on tracking and calorimetry) confirmed the urgent need for a significant increase in manpower and resources • Our committee echoed the comment of one of the collaborations: ‘Ultimately, the greatest R&D risk is that insufficient resources will be directed towards achieving the goals of this plan’ • We hope that the ILC Detector Directorate, working with the funding agencies and lab directors, will help to secure the needed resources, just as the GDE is doing for the machine • We should be very careful not to weaken the R&D groups (in order to support the Engineering Designs) just when they are most in need of support. The ILC physics programme depends on R&D which cannot be completed before about 2012 • Remember Richard Feynman’s words of good advice – ‘Reality has to take precedence over Public Relations, for Nature cannot be fooled’ LCUK - Report on Detector R&D Reviews Chris Damerell