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ILC Accelerator Kaoru Yokoya (KEK) 2013.12.13 KIAS 2013/12/13 KIASWS Yokoya1.

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Presentation on theme: "ILC Accelerator Kaoru Yokoya (KEK) 2013.12.13 KIAS 2013/12/13 KIASWS Yokoya1."— Presentation transcript:

1 ILC Accelerator Kaoru Yokoya (KEK) KIAS 2013/12/13 KIASWS Yokoya1

2 TDR Global TDR Event on Jun Tokyo  CERN  FNAL TDR handed to LCC Director Lyn Evans 2013/12/13 KIASWS Yokoya2

3 Site Down-selection Down selection to Kitakami site announded in August end 2013/12/13 KIASWS Yokoya3

4 ILC Layout Electron source Positron source Damping Rings 2013/12/13 KIASWS Yokoya4 RTML Main linacs BDS

5 2013/12/13 KIASWS Yokoya5

6 Main Linac Key area of ILC – ~2/3 of the total cost TDR specification – Gradient at vertical test Average 35MV/m Accept cavities > % = 28MV/m Q0 > 0.8x10 10 at 35MV/m yield > 90% (Up to 2 surface treatment passes) – Average operating gradient 31.5MV/m Accept the range +/- 20% Q0 > 1xx10 10 at 31.5MV/m 2013/12/13 KIASWS Yokoya6

7 Main Linac Parameters 2013/12/13 KIASWS Yokoya7

8 Progress in 1.3 GHz ILC Cavity Production 2013/12/13 KIASWS Yokoya 8 Progress in EXFEL (800 cavity construction as of 2012/10): (courtesy by D. Reschke: the 2 nd EP at DESY) –RI: 4 reference cavities with Eacc > 28 MV/m, (~ 39 MV/m max.) –Zanon: 3 reference cavities with Eacc > 30 MV/m ( ~ 35 MV/m max.) A. Yamamoto, May2013, ECFA13

9 Global Cavity Gradient Results - EU 2013/12/13 KIASWS Yokoya9 DESY data, D. Reschke et al., SRF2009, TUPPO slides from R.Geng, LCWS12

10 Global Cavity Gradient Results - Americas 2013/12/13 KIASWS Yokoya10 JLAB data, R.L. Geng et al., IPAC2011, MOPC111.

11 Global Cavity Gradient Results - Asia 2013/12/13 KIASWS Yokoya11 KEK data, Y. Yamamoto et al., IPAC2012, WEPPC013.

12 High Gradient Accelerating Cavity 2013/12/13 KIASWS Yokoya 12 Production yield: 94 % at > 28 MV/m, Achieved Average gradient: 37.1 MV/m > cavities needed for 500GeV

13 System Viability Proof DESY: FLASH SRF-CM string + Beam, –ACC7/PXFEL1 9 mA beam,  s, 4.5mA beam, 2012 KEK: STF S1-Global: complete, 2010 –Cavity string : Quantum Beam : 6.7 mA, 1 ms, CM1 & beam, 2014 ~2015 FNAL: NML/ASTA CM1 test complete CM2 operation, in 2013 CM2 + Beam, 2013 ~ /12/13 KIASWS Yokoya13 ILC Spec: 5.8mA, 1ms A. Yamamoto, JPS meeting, Mar.2013

14 E.Kako, 2013/12/05, KEK Euro-XFEL Status 2013/12/13 KIASWS Yokoya14

15 As of Num. of cavities: vendor 123 vendor 256 Europe - XFEL cavity production 2 nd pass: additional high-pressure rinse usable gradient: X-ray limited (dark current) Maximum gradient 2013/12/13 KIASWS Yokoya D. Reschke, LCWS13 15

16 US – Fermilab CM /12/13 KIASWS Yokoya CM-2 features all high gradient cavities ( > 35 MV/m) Cryomodule is installed and cold. Commissioning has started – no results yet New 500 W 2K refrigerator operational 16 M.Harrison, LCWS13

17 US FY CDR Q_0 recipe CM testing CM Prod. First X-rays High Q_0 cryomodule with reduced cryogenics operating costs: Improved cooling capability New cavity surface processing recipe Improved magnetic shielding Adiabatic cool-down process Cryomodule Production– Fermilab & JLAB 17 M.Harrison, LCWS /12/13 KIASWS Yokoya

18 US – LCLS II 2013/12/13 KIASWS Yokoya CM01 CM2,3 CM04 CM15 CM16 CM35 BC1 E = 250 MeV R 56 = -55 mm   = 1.4 %BC2 E = 1600 MeV R 56 = -60 mm   = 0.46 % GUN 0.75 MeV LH E = 98 MeV R 56 = -5 mm   = 0.05 % L0  = * V 0 =97 MV I pk = 12 A L b = 2.0 mmL1  =  22° V 0 =220 MV I pk = 12 A L b =2.0 mm HL  =  165 ° V 0 =55 MV L2  =  21° V 0 =1447 MV I pk = 50 A L b = 0.56 mmL3  = 0 V 0 =2409 MV I pk = 1.0 kA L b = mm LTU E = 4.0 GeV R 56 = 0    0.016% 2-km 100-pC machine layout: Oct. 8, 2013; v21 ASTRA run; Bunch length L b is FWHM 3.9GHz Linac and compressor layout 4 GeV CW SRF Linac based FEL based on ILC cavities at SLAC 35 cryomodules – 280 cavities Gradient 16 MV/m; Q0 2e10 at 1.8K Beam power 1.2 MW max Cryogenic power 5.5 MW Located in the upstream end of the existing 3km tunnel 550 m ~ LCLS-II Length 18 M.Harrison, LCWS13

19 10 year Evolution of STF at KEK 2013/12/13 KIASWS Yokoya19 E.Kako, 2013/12/05, KEK up to ~ 420MeV

20 Remaining Technical Issues for Main Linac Cavity production yield as high as possible Improvement of cavity performance in cryomodule Finalize the coupler design (TTF3/XFEL or STF2 type) Confirmation of the reliability in long term operation (coupler, tuner) Further cost reduction in mass production Higher cavity gradient for Ecm>500GeV 2013/12/13 KIASWS Yokoya20

21 Positron Source Undulator method (adopted in ILC baseline) 2013/12/13 KIASWS Yokoya21 3 possible shemes of positron beam generation Conventional Method – Hit a few GeV electrons on a target, and collect the generated positrons – adopted in many accelerators, well established – Issues in the application to ILC Survivability of the target  OK Emittance of the generated positron  OK (improved DR optics) Transport to DR entrance under study No polarized positron Laser-Compton method (far future)

22 ILC Design (undulator method) Electron energy >150GeV 2013/12/13 KIASWS Yokoya22 Undulator – At the end of the electron linac – Helical, superconducting – Length ~150m (~230m when highly poloarized positron is needed) – K=0.92,  =1.15cm, (B=0.86T on the axis) – beam aperture 5.85mm (直径) Target: rotating titanium alloy Flux Concentrator for positron capture Normal-conducting accelkeration up to 400MeV Polarization ~30% (~60% with photon collimator and longer undulator)

23 Positron Yield Undulator aT the end of electron l;inac  positron yield depends on the electron energy (=center-of-mass energy / 2) 2013/12/13 KIASWS Yokoya23 Positron insufficient for Ee < 150GeV To restore the luminosity, the electron linac is operated at 10Hz: 5Hz for positron production 5Hz for collision

24 Target Wheel of Titanium alloy, diameter 1m Must rotate at 100m/s (2000 rpm) in vacuum Under test at LLNL using Ferromagnet seal Still unsatisfactory – Outgassing spikes still being observed More works needed – market products don’t work 2013/12/13 KIASWS Yokoya24

25 Positron Capture Baseline : Capture by flux concentrator – No change since RDR – But lower the max field 5T  3.5T (simulation showed sufficient) Problem: pulse duration 1ms – Also being tested at LLNL Can be replaced with QWT (Quarter Wave Transformer) – But requires longer undulaort (x1.6 倍 ) – Heavier load on the target 2013/12/13 KIASWS Yokoya25

26 20 triplets, rep. = 300 Hz triplet = 3 mini-trains with gaps 44 bunches/mini-train, T b_to_b = 6.15 n sec DR T b_to_b = 6.15 n sec 2640 bunches/train, rep. = 5 Hz T b_to_b = 369 n sec e+ creation go to main linac Time remaining for damping = 137 m sec Booster Linac 5 GeV NC 300 Hz Drive Linac Several GeV NC 300 Hz Target Amorphous Tungsten Pendulum or Slow Rotation 2640 bunches 60 mini-trains Conventional e+ Source for ILC Normal Conducting Drive and Booster Linacs in 300 Hz operation 2013/12/13 KIASWS Yokoya26 T.Omori

27 Bunch Pattern <-- the 100 ns gap is required to cure an e- cloud problem in e+ DR. =132 bunches T.Omori Moving target still needed but much slower 2013/12/13 KIASWS Yokoya27

28 Issues of the Positron System Undulator Scheme – Rotating target and flux concentrator development at LLNL – Photon collimator for higher polarization Conventional Source – “conventional” but still needs some more R&D – High current, high rep rate driver linac – Moving target (<~ 5m/s) – Flux concentrator – Overall simulation Confirm the positron yield Including capture, bunch compression, beamloading & energy compression Choice of undulator/conventional will not affect the tunnel shape – The driver electron linac for Conventional Source can be installed in the space for undulator+photon drift in the ubdulator scheme – Therefore, we have some couple of years to the deadline of the choice 2013/12/13 KIASWS Yokoya28

29 Moving Target <~5m/sec required (1/20 of undulator scheme) 2 possible schemes being developed at KEK 2013/12/13 KIASWS Yokoya29 bellows seal vacuum air ferromagnetic fluid seal airvacuum 5Hz pendulum with bellows seal rotating target with ferromagnetic seal main issue: life of bellows main issue: vacuum First step prototype being tested

30 Damping Rings Requirements –  x = 5.5  m,  y = 20nm – Time for damping 100ms – First step 1312 bunches, maximum 2625 bunches – bunch-by-bunch injection/extraction 2013/12/13 KIASWS Yokoya30 quadrupole section dipole section Circumference ~3km 1 ring for each of electron and positron in the first step bunch interval ~6ns (if necessary) add one more positron ring when going to 2625 bunches depends on electron cloud 1 electron ring in any case (bunch interval 3ns)

31 Damping Ring Configuration 2013/12/13 KIASWS Yokoya31

32 Damping Ring Requirements 2013/12/13 KIASWS Yokoya32

33 Damping Ring Parameters 2013/12/13 KIASWS Yokoya33

34 Electron Cloud Instability Has been studied at CESR-TA by international team Gave recommendation for the mitigation method (table below) – Arc and wiggler sections requires antichamber – Full power in 3.2km ring needs aggressive mitigation plan No significant difference between 6.4km with 2600 bunches and 3.2km with 1300 bunches ECLOUD`10 (October 13, 2010, Cornell University) /12/13 KIASWS Yokoya

35 Damping Ring Vacuum Chamber Following the recommendation by CESR-TA team, ILC adopts the following chambers Other instabilities are less serious in positron damping ring FII (Fast Ion Instability) is the most important in the electron ring 2013/12/13 KIASWS Yokoya35

36 BDS (Beam Delivery System) Ultimate role of BDS is to focus the beam at the IP, but there lots of devices to do this Machine Protection System Tune-up/emergency dump Collimator Beam diagnostics section (beam energy, emittance, polarization) Muon absorber Crab cavity Feedback system Beam diagnostics after IP (beam energy, polarization) Main beam dump 2013/12/13 KIASWS Yokoya36

37 BDS Layout 2013/12/13 KIASWS Yokoya37

38 BDS Main Parameters 2013/12/13 KIASWS Yokoya38

39 m 50 m LINAC DR ATF2 The ATF2 has been designed, constructed and operated under the international collaboration. ATF2: Beam Focusing Test Facility at KEK 2013/12/13 KIASWS Yokoya

40 ATF2 Goals Beam size at 1.3GeV – Goal 37nm – ~65nm achieved Beam positron stabilization to a few nm by feedback 2013/12/13 KIASWS Yokoya40

41 IP Feedback Bunch interval is long enough for intra-train digital feedback – Advantage of SC collider Large disruption parameter – Dy = /12/13 KIASWS Yokoya41

42 Issues on BDS ATF2 – Beam focus by another factor 2 – Stabilization to ~2nm Design check – beam dumpline – impedances Commissioning strategy – Is the IP beam size monitor needed? Access to IR hall – Access slope in TDR (mountain region) but, is vertical shaft possible? 2013/12/13 KIASWS Yokoya42

43 Access Tunnel Access Hall (Slope <10%) Damping Ring Detector Hall Ring To Main Linac (RTML) e- Main Linac (ML) e+ ML RTML turn-around e- Source e+ Source (Slope <7%) Existing surface road Existing road ( The background photo shows a similar site image, but not the real site.) Surface Structures PM-13 PM-12 PM-10 PM-8 PM-ab PM+8 PM+10 PM+12 PM+13 (Center Campus) PX Kitakami-site cross section Site Specific Design 2013/12/13 KIASWS Yokoya 43

44 CFS Plan Towards the Construction Start 2013/12/13 KIASWS Yokoya A.Enomoto, LCWS13

45 9-year Construction Schedule 2013/12/13 KIASWS Yokoya45

46 From the LCWS Conclusion on CFS The selected site satisfies the TDR conventional designs without any fundamental issues The remaining issues yet to be worked out (such as the path length and positron scheme) will not affect the underground construction and surface facility layout Intensive geotechnical study of the detector hall by a Japanese company. This will be checked with the previous European IR hall analysis 2013/12/13 KIASWS Yokoya46

47 2013/12/13 KIASWS Yokoya47 LCC Pre-IL Accelerator Organization Electrical Support Japan Electrical Support Japan Mechanical Support Japan Mechanical Support Japan Cryogenic Support Japan Cryogenic Support Japan SRF ww SRF ww Conventional Facilities ww Conventional Facilities ww LC Project Office (KEK) Controls & Computing Japan Controls & Computing Japan Safety Japan Safety Japan Accelerator Design & Integration ww Accelerator Design & Integration ww Electron Source ww Electron Source ww Positron Source ww Positron Source ww Damping Rings ww Damping Rings ww RTML & bunch compressor ww RTML & bunch compressor ww Main Linac ww Main Linac ww Beam Delivery ww Beam Delivery ww Machine-Detector Interface ww Machine-Detector Interface ww Domestic Programs & System Tests Domestic Programs & System Tests Project Management Baseline, Schedule Cost, EDMS Technical Board Technical Board LCWS13 Mike Harrison

48 Summary Site down-selected to Kitakami, Japan Site-specific design going to start There are some remaining issues – positron – Final focus (ATF2) New organization under LCC-ILC box (chaired by Mike Harrison) is being formed 2013/12/13 KIASWS Yokoya48


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