1 A_RD_2A_RD_2 Design of the linear collider machine-detector interface and ATF-2 at KEK Ph.Bambade, J.Brossard, O.Dadoun, C.Rimbault, M.Alabau Pons, A.Jeremie, B.Bolzon, N.Geffroy, F.Cadoux, T.Tauchi, J.Urakawa, T.Kume, R.Sugahara, A.Sugiyama, T.Sanuki Andrea JEREMIE

2 ATF2 ATF2 objectives: 1.37nm vertical size and 2.8  m horizontal size beam at focal point in a reproducible and stable manner => flat beam as in ILC(a.r.80 for ATF2 and 110 for ILC) 2.stable trajectory (  <2nm) and intra-train feedback like in future ILC ILC demonstrator! Schedule: Installation: Beam: October 2008

3 ATF2

4 Mechanical stabilisation of Final Doublet

5 Mechanical stabilisation QD0:400kg mover: 25kg T-plate:10kg CERN CLIC stabilized table FFTB Magnet Mover

6 Mechanical stabilisation Two main topics: 1.Measurements with magnets and movers 2.Study FD support

7 Mechanical stabilisation 1.Measurements with magnets and movers 4 movers arrived from SLAC: need some modifications to fix and adjust to CLIC table Measure vibrations with mock weight and eventually a real ATF2 FD magnet Modify movers to adjust to beam height when FD support finalised Mock weight (lead bricks) has arrived at Annecy and has been placed on table ready for measurements Mover T-plate being done: machine- shop time reserved and material ordered

cm ( ) cm Mechanical stabilisation The movers will be modified to agree with beam height: here the first draft when using the CLIC table to reduce the height by 8cm cm

9 Mechanical stabilisation Study CLIC table performance at low frequency Need to be compatible with precise measurement of beam shape and size at IP Finalise FD performance requirements at ATF2 Asked for money to transport table, but a new support will be sent when study finished (in time for beam commissioning) 2. Study FD support

10 Isolator:  Stiff rubber: Passive damping  One vertical geophone/actuator pair  Two horizontal geophone/actuator pairs Honeycomb support structure User Interface Controller : to provide communications with and diagnostics of the STACIS 2000 system Isolator FD support Initial idea: use CERN CLIC stabilized table Active damping This table has been used with success to stabilize at nm level in the 1-50Hz range by CERN team! But ATF2 FD needs to be stable in the Hz.

~Same response Amplification Damping Below 0.5Hz: No amplification or damping on the table Above 0.5Hz: Amplification and damping begins only above ~30Hz Below 0.8Hz: Amplification on the table Above 0.8Hz: Damping on the table  Factor 7 of damping above 1.5Hz Vibrations of the passive table Vibrations of the active table Vertical direction: Integrated RMS CERN table behaviour to ground motion

12 Proposal1 :Rigid mount on floor Mount both interferometer and magnet rigidly on floor without any stabilizer Interferometer Final magnet (mount table) Electron beam Floor Interference fringes Rigid mount Confirm rigidity of interferometer body Confirm rigidity of mount Estimate effects of magnet originated vibration Advantage Tolerant for slow (coherent: ~0.1Hz?) floor motion Simple & low cost Disadvantage Affected by high-speed (incoherent:1Hz~?) floor motion Affected by distortion of Interferometer body and mounts Affected by magnet (including cooling water, etc.) vibration Proposal

13 Polymer concrete Bolting Less amplification factor at lower frequencies for concrete polymer Support structure and rigid fixing

14 Vibrations transmissibility study between table and floor Above 20Hz: Increase of table transfer function magnitude  Ground motion amplification done by the table up to a factor 11 at 68Hz Up to 20Hz: Table transfer function magnitude around 1  No big amplification or damping done by the table Magnitude of table transfer function measured at LAPP: amplification

15 Compare measurements to simulations First eigenfrequency at 56.2Hz: Well lower than in free-free configuration!!! In agreement with transfer function measurements Simple block simulation done by Nicolas Geffroy: Full block with the table dimensions (240*90*60cm) Calculation of the density to obtain the table weight (700kg) Young modulus chosen (rigidity) to obtain the first eigenfrequency of the table in free-free configuration (230Hz)

16 Relative motion between table and floor at ATF Ring  Integrated relative motion between floor and table at ATF Ring using table transfer function: - Above 0.1Hz: 5.95nm  Below ATF tolerances (6nm)!!! - Above 50Hz: 0.78nm  Negligible Data from ATF floor What would happen if we use the block in ATF2?

17 Schematics of Shintake Monitor Measure beam size using phase (=position and period) of interference fringe as a reference Interference fringes as a reference Electron beam to be measured Scanning electron beam  -ray modulated by interference fringes

18 Analysis results for deformation mode of interferometer (1 st ~5 th ) 1st (42.4 Hz, Twist)2nd (53.7 Hz, Bend)3rd (73.7 Hz, Twist) 4th (91.9 Hz, Twist)5th (98.1 Hz, Twist) Hit by impulse hammer and measure response by Acc. Sensor (Herz co. ltd. ) Large motion Small motion

19 GEANT 4, commissioning strategies and crossing angle studies

20 Pair background with almost no Pt Optimization of IR design Inside diameter of TPC and FCAL influence on background => influence on the backscatter from beam calorimeter (BCAL) of Extraction hole =>pair background from the solenoid magnetic field

21 Anti-DID insert winding equipment combining two Dipoles. The charged particle of low energy is led to Extraction hole. plain solenoidsolenoid with anti-DID Low high Low e-e+e-e+ Optimization of solenoid magnetic field

22 FCAL Inner Radius FCAL CH2MaskBCAL Support Tube Optimization of the inside diameter of FCAL Avoid gammas in FCAL which come from BCAL Initial value of the aperture was optimized by calculation=> verification with simulation.

23 Collider motivations for small crossing-angle ILC IR very small 0 – 2 mrad large 14 – 25 mrad injection & extraction challenges & remedies approaches & risks shared magnets  coupled design large L loss :  x z   crab-crossing (R&D) non-axial in solenoid  DID / anti-DID & post / pre-IP bumps post-IP losses  careful optics & collimation  large magnet bores  electr. separators emphasize post-IP beam adds pre-IP constraints preserve pre-IP beam reflected background separate channels Orsay+Saclay workshop on design challenges of the small crossing-angle IR: October Strong contribution to the ILC IR solutions

24 Beam instrumentation successful exchange of students and young scientists which should be encouraged at both sides

25 Travelling financed by AIL France-Japan Meeting in Annecy: 20 participants from France, Japan, CERN, USA, UK and Spain October 9-11, rd ATF2 ATF2 Project Meeting in KEK Student trip to KEK for instrumentation work This Meeting

26 Bid for A_RD_2 : Collaboration on the ATF2 project at KEK and on the ILC Machine Detector Interface Members (same institutes as for 2006): Ph.Bambade, J.Brossard, O.Dadoun, C.Rimbault, M.Alabau Pons, Y.Régnier (LAL/France) A.Jeremie, F.Cadoux, N.Geffroy, B.Bolzon (LAPP/France) T.Tauchi, J.Urakawa, R.Sugahara, S.Kuroda, T.Okugi, T.Kume(KEK/Japan) A.Sugiyama (Saga University/Japan) T.Sanoki (Tokyo University/Japan) M.Verdéri, H.Guler => new participant from LLR/France

27 Work on beam correction algorithms (LAL and KEK) characterize the transverse beam phase-space extracted from the ATF damping ring : where does the observed significant increase in vertical emittance of extraction line come from? beam tests in the Fall of 2007 and first months of Studies to provide a suitably stabilized support for the FD ( LAPP, KEK and SLAC) characterization of ground vibration at KEK and transfer function of setup at LAPP. send the final system to KEK at the end of 2007 or beginning of 2008 tests at LAPP and final at KEK Estimation of beam halo induced background (LLR, LAL, KEK and RHUL in the UK). GEANT4-based BDSIM tool developed for the ILC : model backgrounds from scattered low-energy particles in several instruments (e.g. the “Shintake”). Suitable event-biasing techniques should be implemented. The results are essential to optimize the final experimental setup and to validate the methodologies developed for ILC. Machine Detector Interface design (LAL and KEK), define and optimise the Interaction Region and Forward Detectors evaluate different crossing-angle solutions at the IP from the point of machine and detector & physics Bid for A_RD_2 : Collaboration on the ATF2 project at KEK and on the ILC Machine Detector Interface The present proposal is a re-application to continue and expand our existing collaboration within the ATF2 project.

28 Budget Plan French TeamsJapanese Teams Item Euro Supported by Item k Yen Supported by Travel+per -diem for each trip 2500€Travel+per- diem for each trip 333 K¥ No of trips LAL 37500CNRSNo of trips62000KEK No of trips LAPP 37500CNRS No of trips LLR 25000CNRS Total Bid for A_RD_2 : Collaboration on the ATF2 project at KEK and on the ILC Machine Detector Interface

29 Conclusion Very fruitful work: Share experience with accelerators Share expertise in signal analysis and vibration data and design of FD support is advancing well Regular phone or video meetings Travel to meet and work during workshops and ATF2 project meetings Planning more extended visits to the ATF2 site at KEK at the end of 2007 and in 2008