The Linear Collider: a UK perspective

2. The Linear Collider: a UK perspective Grahame A. Blair Edinburgh, 8th February 2006 • Introduction to the machine • Detectors • UIK activities • Timescales • Some key Physics (time ?) • Summary

3. www.linearcollider.org

4. Superconducting Niobium Cavities

5. Y. Kokoya, GDE Frascati 2005

6. Damping Rings Beam Delivery System Main Linac (RF) Particle Sources Generic Linear Collider < ~20 km > < ~4 km > DR Circumf. Baseline: 6km

7. Damping Process

8. Y. Kokoya, GDE Frascati 2005

9. A Possible Layout • Approximately follow earth’s curvature • Upgrade path to ~1 TeV

10. LC for Physics Purposes: • e+e- collisions with √s tuneable 0.5 – O(1) TeV • e-e- mode. • Polarisation: e- 80% (L/R); e+ 60% (?). • Possibility to run at √s ~ 90 – 160 GeV (“GigaZ”) • Luminosity 3-6.1034 cm-2 s-1  specific analyses can assume up to about 1 ab-1 Also possible/important; Compton scattering to produce  or e

11. Bunch Interactions e- e+ Schulte • Increase in luminosity (×~2) • Beamstrahlung  Lumi. Spectrum

12. Luminosity Spectrum • sharp peak • approx same as ISR (tuned) – few % in tail • for 0.5-1 TeV machines TESLA TDR

13. Precision Measurement of the Top Mass Precision measurement of fundamental particle properties The top quark is the heaviest: most sensitive to new physics Cross section (pb) Mtop=175 GeV 100 fb-1 per point Statistical Precision ~0.05 GeV 0.02% Etot(GeV) Martinez et al.

14. e-R e+L e-R e-R R R Initial State • W-production suppressed • s-wave production of charginos ~  sharp threshold • Specific polarisations for specific couplings (eg SUSY) http://www.ippp.dur.ac.uk/~gudrid/power/ • s-wave production of selectrons ~  sharp threshold • Direct production of higgs

15. Worldwide LC Studies http://blueox.uoregon.edu/~lc/wwstudy/ http://blueox.uoregon.edu/~lc/alcpg/ http://acfahep.kek.jp/

16. Worldwide studies (2) http://www.desy.de/conferences/ecfa-lc-study.html http://clicphysics.web.cern.ch/CLICphysics/

17. The Detectors http://physics.uoregon.edu/~ lc/wwstudy/concepts/

18. Number of IPs • 2 IPs + 2 detectors is the baseline. • The cost of 2nd IP (beamline + exp.hall) corresponds to the energy 14-19% of 500GeV (change of tunnel cost not included). Caveats: Total cost estimation from 3 regions agree well but the cost of individual components scatter in wide ranges. • This means 405-430 GeV LC with 2IP is comparable in cost with 500GeV LC with 1 IP It is possible that 1 IP will become the baseline – The physics community needs to make its case clear Adapted from Y. Kokoya, GDE Frascati 2005

19. SID • Design philosophy • Aim for SiW calorimeter • with best possible resolution • Keep radius small to make this affordable • Compensate by high B- • field (5 T) and very precise tracking (Si) • Fast timing of Silicon to suppress background

20. LDC • Design philosophy • Fine resolution calorimeter for particle • flow • Gaseous tracking for • High tracking efficiency • and redundancy • Large enough radius • and high enough B-field • (B=4 T) to get required • momentum resolution

21. GLD • Design philosophy • Large radius for particle-flow optimisation • Gaseous tracking for • High tracking efficiency • and redundancy • Fine grained scintillator-tungsten calorimeter • Moderate B-field (3 T)

23. Energy Flow in Jets Some processes where WW and ZZ need to be separated without beam constraints. Requires ΔE/E~30%/E

26. S. Worm, LCUK meeting, Oct 05

28. Particle/Machine Physics • The LC will be a very challenging machine • Particle physicists are taking part in machine studies • Beam diagnostics and control • Background estimates • Design studies • The particle physics programme now goes beyond “what comes out of the IP”.

29. UK funding for accelerator science for particle physics 2004 - 2007 UK funding agency, PPARC, secured from Govt. £11M for ‘accelerator science’ for particle physics, spend period April 04 – March 07 Called for bids from universities and national labs; large consortia were explicitly encouraged LC-Beam Delivery £9.1M + 1.5M CCLRC UKNF £1.9M 2 university-based accelerator institutes: John Adams: Oxford/RHUL Cockroft: Liverpool, Manchester, Lancaster, NW dev. agency. Funding period ends in 2007; new bid will be finalised in July 2006.

30. LC-ABD Collaboration • Bristol • Birmingham • Cambridge • Dundee • Durham • Lancaster • Liverpool • Manchester • Oxford • QMUL • RHUL • University College, London • Daresbury and Rutherford-Appleton Labs; 41 post-doctoral physicists (faculty, staff, research associates) + technical staff + graduate students

31. UK Interests:Beam Delivery System

32. ~3km Beam Delivery System • Full simulations • Backgrounds • Optimisation • Precision Diagnostics • Energy • Polarisation • Luminosity

33. 2 mrad Optics Design • Final Focus and extraction line optimized simultaneously • Quadrupoles and sextupoles in the FD optimized to • cancel FF chromaticity • focus the extracted beam SLAC-BNL-UK-France Task Group O.Napoly, 1997 QF1 pocket coil quad : C. Spencer D. Angal-Kalinin

34. BDSIM Beamlines are built of modular accelerator components Full simulation of em showers All secondaries tracked Screenshot of an IR Design in BDSIM

35. BDS: Muon Trajectories Concrete tunnel 2m radius BDS View from top

36. Multi-Seed Luminosity Studies with the ILC Simulation Model LUMI Feedback Optimisation (Position + Angle) 350 GeV CME ANG + IP Fast Feedback 500 GeV CME G. White

37. FONT3 installation on ATF beamline BPM processor board FEATHER kicker Amplifier/FB board ATF beamline installation June 05 P. Burrows

38. Bunch-Bunch Interaction Simulations TESLA parameters PINIT=1.0 low Q parameters PINIT=1.0 Before interaction During interaction After interaction

39. Laser-wire: Principle

40. Laserwire - PETRA + UCL 11.2.05 System recently upgraded

41. ATF-LW Vacuum Chamber Built at Oxford DO + Workshop Vacuum Tested At DL

42. Superconducting Helical Undulator Parameters Superconducting bifilar helix First (20 period) prototype constructed (RAL) Cut-away showing winding geometry

43. Wakefields Change in beamline aperture θ • Wake-fields from the head of the bunch can disturb the tail • Wake-fields from earlier bunches can disturb later ones • (such effects can also be useful – eg. Smith-Purcell radiation)

44. Wakefield box 1500mm ESA sz ~ 300mm – ILC nominal sy ~ 100mm (Frank/Deepa design) Magnet mover, y range = 1.4mm, precision = 1mm N. Watson

45. 38 mm h=38 mm L=1000 mm a r=1/2 gap As per last set in Sector 2, commissioning Extend last set, smaller r, resistive WF in Cu 7mm cf. same r, tapered

46. Overview of LC Projects Essentially independent of Linac-technology

47. 2005 2006 2007 2008 2009 2010 Global Design Effort Project Baseline configuration Reference Design Funding The GDE Plan and Schedule Technical Design globally coordinated regionial coord ILC R&D Program expression of interest Siting Hosting sample sites FALC International Mgmt ICFA / ILCSC

48. Machine Summary • The ILC is now being defined. • The Baseline is under “Configuration Control” • Global Design Effort is in place, with a very active programme aiming at a Reference Design Report at end of 2006. • UK is involved in two detector projects and an exciting range of accelerator R&D. • The next round of accelerator-related bids are due for this summer.  a great time to get involved.

50. ILC Physics: