1. Accelerator Studies for Linear Colliders Jim Clarke, ASTeC, Daresbury Laboratory PPAP, Birmingham 14 th July, 2009

2. The ILC 500 GeV Based upon SC RF Linacs

3. CLIC Layout (3 TeV) Drive Beam Generation Complex Main Beam Generation Complex Delahaye Up to 3 TeV Based upon NC RF Linacs & novel RF power source

4. Beam Parameters ILC (500)CLIC (3 TeV) Electrons/bunch 0.750.37 10**10 Bunches/train 2820312 Train repetition rate 550Hz Bunch separation 3080.5ns Train length8680.156us Horizontal IP beam size65545nm Vertical IP beam size60.9nm Longitudinal IP beam size30045um Luminosity26 10**34 ILC & CLIC have a lot more in common than it appears at first glance ! UK studies are applicable to both.

5. UK LC-ABD Collaboration Abertay BirminghamDaresbury Lab. Cambridge Dundee Durham Lancaster Liverpool Manchester Oxford University College London Royal HollowayRutherford-Appleton Lab.

6. UK LC-ABD Collaboration Abertay BirminghamDaresbury Lab. Cambridge Dundee Durham Lancaster Liverpool Manchester Oxford University College London Royal HollowayRutherford-Appleton Lab.

7. LCABD expertise Beam delivery system:  accelerator physics + design integration: low-emittance transport  crab cavity  beam dumps  collimation system  instrumentation: emittance measurement, feedback, control  vacuum system Positron source:  undulator  photon target  system design Damping rings:  vacuum  beam instabilities  system design UK requested to provide leadership + management in key areas

8. LCABD expertise Beam delivery system:  accelerator physics + design integration: low-emittance transport  crab cavity  beam dumps  collimation system  instrumentation: emittance measurement, feedback, control  vacuum system Positron source:  undulator  photon target  system design Damping rings:  vacuum  beam instabilities  system design UK requested to provide leadership + management in key areas APPLICABLE TO ILC AND CLIC!

9. Designed, modelled and tested collimators at SLAC ESA facility Example: Collimator design + testing Deflection (  rad) Collimator y (  m) T480 (prelim.) Jul. ’06 run T480 (prelim.) Jul. ’06 run Kick factor (V/pC/mm) E.M. predictions GdfidL vs. ECHO (ESA collims. 1- 8) E.M. predictions GdfidL vs. ECHO (ESA collims. 1- 8) beam Made most detailed Simulations of spoiler jaw damage to date. Made most detailed Simulations of spoiler jaw damage to date. J. Smith et al

10. Example: Crab Cavity Development Design, Model, Measure

11. Example: Crab Cavity Stability Verification Test stand at Cockcroft Institute

12. EuCARD: Crab Cavities CLIC-CC R&D:  Multi-cell 11.9942 GHz dipole- mode cavity developed.  Various mode damping schemes investigated: Choke Waveguide  An optimised 7-cell, waveguide damped design being investigated further. LHC-CC R&D:  Both Phase-I (800 MHz) and Phase-II (400 MHz) solutions being developed.  Cavity modelling, mode damping and multipactor investigations ongoing. Phase-I Phase-II LLRF R&D:  CLIC-CC and LHC-CC phase control models under development.

13. Example: Positron Source Undulator Design of superconducting helical undulator  Magnet  Vacuum  Wakefields  Synchrotron Radiation  Cryogenics Several short prototypes fabricated and tested UK solution adopted by ILC Full scale cryomodule constructed at RAL Skills gained are now being applied to light sources such as Diamond EuCARD is supporting UK development of Nb 3 Sn undulator development

14. Example: Positron Source Undulator ILC Positron Source undulator with RDR Parameters under test at RAL

15. Example: Positron Target Rapidly rotating photon target in magnetic field causes major eddy current losses Prototype constructed at Cockcroft Institute to quantify effect Comparison with alternative simulations

16. Example: Damping Ring Design and Integration Gate Valves Electron Vessel Positron Vessel Typical Gate Valve Supports FixedSliding Straight Cylindrical Vessel Tapered Vessel Ante-Chambered Vessel Tapered Vessel Pumping Port BPM Station (Electron) BPM Station (Positron) Gate Valves Engineering of ILC Damping Ring including vacuum design being led by Cockcroft Institute

17. Example: Damping Ring Design and Integration BPM Reference Pillars Positron End ViewElectron End View BPM Bellows Arrangement Fitted on all BPM Blocks Reference Pillar provides reference points for the beam orbit. Position Encoders monitor any motion of BPMs from thermal or mechanical effects Similar system to Diamond Position Encoders Digital Length Gauges 0.5 um Resolution Ground Surfaces

18. Example: BDSIM Software Collimation Efficiency BDS Optimisation Shielding Muon production and tracking MDI optimisation Radiation levels Accelerator style tracking incorporated on top of Geant4 New processes are being added (recently wake-fields) Also currently being applied to LHC plus upgrades CLIC BDS collimation with secondary particle production + wakefields Detector IR in BDSIM Nucl. Instr, Meth. A 606 (2009) 708-712 Phys Rev ST-AB (2009) accepted

19. Example: CLIC Main Linac  EuCARD – design of main accelerating linac structures incorporating wake function suppression (Manchester). CLIC needs 142,812 of these!  Design focusses on moderate damping combined with strong detuning of interleaved structures.  Structures will be built and measured on the CTF3 modules – design to be verified!  Early design indicates potential to reduce damaging pulse temperature heating CLIC Module for CTF3 Potential Univ. Manchester/CI Structure for CFT3 Module R Jones

20.  EuCARD - 3.9 GHz (third harmonic) bunch shaping cavities  Cryomodule, consisting of four 3.9GHz cavities, will be installed in 2010 at FLASH photoinjector downstream of the first 1.3 GHz cryomodule (consisting of 8 cavities).  3.9 GHz cavities will be measured, HOMBPM electronics will be custom-built and alignment inferred from HOM read-outs Third harmonic bunch shaping cavity –designed at FNAL NLSF design (UniMan/CI) compared to existing designs  New optimised design, NLSF (New Low Surface Field) for main 1.3 GHz linacs with greater stability (larger bandwidth) R Jones Example: RF Cavities

21. Example: CLIC Drive Beam Quads CLIC drive beam has a quadrupole magnet every meter  42,000 quads !!!  Major cost & time to build  Huge power & heating problems Novel solutions being investigated Applicable to many accelerators ASTeC/CERN collaboration Two possible permanent magnet solutions Ben Shepherd

22. ATF2 Scaled down model of LC final focus @ KEK, Japan Test Facilities: ATF2

23. 23 ATF2 at KEK - Aim for: Challenging μm scale ILC/CLIC specification PETRA3 at DESY - Aim for: Reliability Speed Generic technology also applicable to Linac4/SPL/ESS Ultra-fast scanning using EO: Beam images and profiles during scan Nucl. Instr, Meth. A 592 (2008) 162-170 Phys Rev ST-AB 10 (2007) 112801 Appl. Phys. Lett. 94 (2009) 1 Test Facilities: Laser Wire

24. KickerBPM 1 Digital feedback Analogue BPM processor Drive amplifier BPM 2 BPM 3 e- Test Facilities: FONT4 prototype at ATF Fast feedback systems needed for intra-bunch stability Test with beam at ATF

25. KickerBPM 1 Digital feedback Analogue BPM processor Drive amplifier BPM 2 BPM 3 e- Test Facilities: FONT4 prototype at ATF Fast feedback systems needed for intra-bunch stability Test with beam at ATF

26. Test Facilities: MONALISA @ ATF2 Test stand at Oxford N.B. A CSM is also being designed for CLIC Bowtie arrangement Compact Straightness Monitor (CSM) Combined interferometers give 3D position measurement CSM at ATF-2 between: Shintake monitor QD zero (final quadrupole) Measures relative vertical displacements at the nanometre level 100 mm Retro-reflectorsLaser launch

27. Test Facilities: optics and simulation ATF2 major test facility for ILC like optics, diagnostics, operations  Currently commissioning  Feedback operation essential for stable ILC like focus  Verify optics models, online verification of optical models on running accelerator FONT ATF2 simulationOptics model verification

28. Test Facilities: CTF3 DL CLEX 2007-2009 building in 2006/7 2004 2005 2006/7 Thermionic gun CR TL2 2008 30 GHz production (PETS line) and test stand Photo injector / laser tests from Oct. 2008 Linac DF F D D F F DF D D F D DF D DF D DF D F D F DFD F DFDF D FDF DF D FDFD DF FF DD D FF DD FF FF DF D DF D D F DD F D DF D DF D DF D DF D DFDF D F D FDF D FDFDF D FDF D F D F D F D F DFDFD F D F DFDFDFDF D F D FDFDF DF D DF D FDFD FDFD CTF2 CLEX

29. First Experimental results Horizontal polarization component Advantages: Non-Invasive method Instantaneous emission Large emission angles Single shot measurements Coherent Diffraction Radiation (CDR) appears when a charged particle moves in the vicinity of a medium in the wavelength range comparable to or longer than an electron bunch. CDR setup at CTF3 Target orientation angle (deg) Target position from the beam line (mm) Test Facilities: CDR Monitor on CTF3

30. LCABD Status Investment (PPARC, CCLRC, STFC) allowed LCABD to gain a major strategic position in linear colliders Expertise applicable to light sources (and more generically) Funding was cut by 75% in STFC Delivery Plan (Dec 2007)  £4M to £1M Currently maintaining (some) critical leadership + R&D  Without new investment the skills base will erode rapidly Opportunity now to benefit from step-change in CERN position on linear colliders UK work is fully aligned with ILC/CLIC collaboration  LCABD submitted SoI to STFC (May 09)  SoI requested 6FTEs (RA & technical staff) + £100k p.a. to start 2010 so UK can make significant contribution to CLIC TDR