ATF2 ILC Final Focus Test Beam Line at KEK-ATF References : ATF2 Proposal, KEK Report ATF2 Proposal Vol.2, KEK Report ホームページ：

110 authors (25 reseach institutes) in the proposal

ATF2 Final Goal Ensure collisions between nanometer beams; i.e. luminosity for ILC experiment FACILITY construction, first result ATF2/KEK ? FFTB/SLAC Optics Local chromaticity correction scheme; very short and longer L* (β * y =100μm, L tot =36.6m) Conventional (separate) scheme; non-local and dedicated CCS at upstream; high symmetry; i.e. orthogonal tuning (β * y =100μm, L tot =185m) Design beam size 34nm / 2.2μm, aspect=65 (γε y =3 x m) 60nm / 1.92μm, aspect=32 (γε y =2 x m) Achieved ? 70nm ( beam jitter remains !) Reduction of Risk at ILC Optics and bean tuning Stabilization

Mode-I A. Achievement of 37nm beam size A1) Demonstration of a new compact final focus system; proposed by P.Raimondi and A.Seryi in 2000, A2) Maintenance of the small beam size (several hours at the FFTB/SLAC) Mode-II B. Control of the beam position B1) Demonstration of beam orbit stabilization with nano-meter precision at IP. (The beam jitter at FFTB/SLAC was about 20nm.) B2) Establishment of beam jitter controlling technique at nano-meter level with ILC-like beam (2008 -?)

Optics v3.5, 1 July m reduction of dispersionfinal focusdiagnostic west テキスト

ATF2 beam line and ATF extraction line ATF2 beam lineATF extraction line ATF2 beam line and ATF extraction line

5 Wire Scanners or Laserwires 5 Strip-line BPMs 3 Screen Monitors BSM CLIC table H V VHV 5 Steering (V,H) Magnets SF5 H 53 m 22 Quadrupoles(Q), 5 Sextupoles(S), 3 Bends(B) in downstream of QM16 QM16 SD4SF6B5B2 B1 QD0 QF1 SD0 SF1 All Q- and S-magnets have cavity-type beam position monitors (QBPM). 3.5m IP Shintake Monitor ( beam size monitor, BSM with laser interferometer ) QBPMs (100nm ) and IPBPM ( 2nm ) at IP MONALISA ( nanometer alignment monitor with laser interferometer ) Laserwire ( beam size monitor with laser beam ) IP intra-train feedback system with latency of less than 150ns Magnet movers for Beam Based Alignment (BBA) High Available Power Supply (HA-PS) system for magnets Magnets and Instrumentation at ATF2

Optics at ATF2 IP electron beam D F SF6SF5 SD4 SF1 SD0 B1B2B5

Q-magnet Mover Concrete Support QBPM in a Q-magnet (IHEP, SLAC KEK) (SLAC) (KEK) (KEK, PAL, SLAC)

Example : a power system with Ethernet control that will provide 200A in a 4 out 5 redundant module configuration. HA-PS system ( SLAC ) for a bend 200ms ΔB=-100G B=3.1kG Voltage Test result with 3+1 system (150A) switch off 1 module short time : 2-3ppm long time : 5ppm temperature : 2.5ppm/ ℃

A.Jeremie Bloc:61 Foot:26.5 Total:87.5 Length:240 Width:90 Values are in cm and measured directly on the table with a tape-measure. Static load capacity per foot (there a 4) 182 kg to 1590 kg. Honeycomb bloc has a weight of 731kg. CERN Stacis 2000 (CLIC) table currently in Annecy, France. (LAPP, CERN)

IP-BPM Wave guide X Port Y Port Sensor Cavity Beam Pipe Slot Rectangular cavity for X-Y isolation (-50dB) 2 Cavities in 1 block 2 Y ports and 2 X ports in 1 Cavity 11 cm 14 cm (61.45 x x 6mm 3 ) (6 x 12 mm 2 ) Goal : 2nm position resolution Residual vs Time Residual of (Y2I – Y2I predicted ) 1h Preliminary beam test result : Position resolution for 1 hour run (stat.) (sys.) nm ( ICT = 0.68 x e - /bunch, dynamic range = 4.96 um ) (KEK, KNU)

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 (Univ. of Tokyo, KEK)

IP intra-train feedback system (Oxford) Last line of defence against relative beam misalignment Measure vertical position of outgoing beam and hence beam- beam kick angle Use fast amplifier and kicker to correct vertical position of beam incoming to IR FONT – Feedback On Nanosecond Timescales

( RHUL, Oxford) Laserwire

MONALISA Need 2 tools, both with nm type resolutions over a few m. –Straightness Monitor measuring motion perpendicular to line of sight. Main tool to measure the relative motion of objects –Distance meter: Frequency scanning interferometer Can also provide perpendicular measurements if several measurements are combined to do triangulation. –Combine both measurements into one system! MONALISA to monitor the relative displacement between QD0 and Shintake monitor at Nanometer (Oxford) Interference pattern sensitive to perpendicular motion of retro-reflector distance meter Retro-reflector Monitoring of Alignment and Stabilization with high Accuracy

Cost Breakup, 26 Jan.07 magnets power supplies magnet supports including movers alignment vacuum control feedback Q-BPMs laserwire Shintake monitor CF :Infrastructure CF:floor, shield etc. Total 5.7 Oku-yen commissioning tools Monalisa

ATF2 Schedule PresentATF2 ON 1. International Construction and Operation; Mini-ILC 2. Forefront of Accelerator Technological R&D 3. Human Resource Development for ILC 4. Commissioning in October 2008