ATF 2 ILC Final Focus Test Beam Line
ATF 2 ILC Final Focus Test Beam Line at KEK-ATF References : ATF 2 Proposal, KEK Report 2005 -2 ATF 2 Proposal Vol. 2, KEK Report 2005 -9 ホームページ:http: //atf. kek. jp/collab/ap/projects/ATF 2/index. php
110 authors (25 reseach institutes) in the proposal
ATF 2 Final Goal Ensure collisions between nanometer beams; i. e. luminosity for ILC experiment Reduction of Risk at ILC FACILITY construction, first result Optics ATF 2/KEK 2005 -07 -08? Local chromaticity correction scheme; very short and longer L* (β*y=100μm, Ltot=36. 6 m) Design beam size 34 nm / 2. 2μm, aspect=65 (γεy=3 x 10 -8 m) Achieved ? Optics and bean tuning Stabilization FFTB/SLAC 1991 -93 -94 Conventional (separate) scheme; non-local and dedicated CCS at upstream; high symmetry; i. e. orthogonal tuning (β*y=100μm, Ltot=185 m) 60 nm / 1. 92μm, aspect=32 (γεy=2 x 10 -6 m) 70 nm ( beam jitter remains !)
A. Mode-I Achievement of 37 nm beam size A 1) Demonstration of a new compact final focus system; proposed by P. Raimondi and A. Seryi in 2000, A 2) Maintenance of the small beam size (several hours at the FFTB/SLAC) Mode-II B. Control of the beam position B 1) Demonstration of beam orbit stabilization with nano-meter precision at IP. (The beam jitter at FFTB/SLAC was about 20 nm. ) B 2) Establishment of beam jitter controlling technique at nano-meter level with ILC-like beam (2008 -? )
Optics v 3. 5, 1 July 2006 final focus diagnostic reduction of dispersion west 6 m テキスト
ATF 2 beam line and ATF extraction line ATF 2 beam line ATF extraction line
M a g n e ts a n d In s tru m e n ta tio n a t A T F 2 22 Quadrupoles(Q), 5 Sextupoles(S), 3 Bends(B) in downstream of QM 16 All Q- and S-magnets have cavity-type beam position monitors (QBPM). 3 Screen Monitors 5 Strip-line BPMs 5 Wire Scanners or Laserwires 5 Steering (V, H) Magnets 53 m QM 16 VH 3. 5 m BSM QD 0 QF 1 SD 0 HV H V B 1 B 2 SD 4 SF 5 B 5 SF 6 CLIC table IP Shintake Monitor ( beam size monitor, BSM with laser interferometer ) QBPMs (100 nm ) and IPBPM ( 2 nm ) 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 150 ns Magnet movers for Beam Based Alignment (BBA) High Available Power Supply (HA-PS) system for magnets
Optics at ATF 2 IP D SF 6 SF 5 B 5 F B 1 B 2 SD 0 SF 1 SD 4 electron beam
Q-magnet (IHEP, SLAC KEK) Mover (SLAC) Concrete Support (KEK) QBPM in a Q-magnet (KEK, PAL, SLAC)
HA-PS system ( SLAC ) • Example : a power system with Ethernet control that will provide 200 A in a 4 out 5 redundant module configuration. Test result with 3+1 system (150 A) switch off 1 module B=3. 1 k. G ΔB=-100 G for a bend 200 ms Voltage short time : 2 -3 ppm long time : 5 ppm temperature : 2. 5 ppm/℃
CERN Stacis 2000 (CLIC) table currently in Annecy, France. A. Jeremie Length: 240 Width: 90 Bloc: 61 Total: 87. 5 Foot: 26. 5 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 731 kg. (LAPP, CERN)
IP-BPM Goal : 2 nm position resolution (KEK, KNU) Rectangular cavity for X-Y isolation (-50 d. B) • 2 Cavities in 1 block • 2 Y ports and 2 X ports in 1 Cavity X Port Sensor Cavity (61. 45 x 48. 58 x 6 mm 3) 11 cm 14 cm Y Port 14 cm Wave guide Beam Pipe (6 x 12 mm 2) Slot Preliminary beam test result : Position resolution for 1 hour run 8. 72 +- 0. 28 (stat. ) +- 0. 35 (sys. ) nm 1 h ( ICT = 0. 68 x 1010 e-/bunch, dynamic range = 4. 96 um ) Residual of (Y 2 I – Y 2 Ipredicted) Residual vs Time
(Univ. of Tokyo, KEK) Schematics of Shintake Monitor Measure beam size using phase (=position and period) of interference fringe as a reference Interference fringes as a reference γ -ray modulated by interference fringes Scanning electron beam Electron beam to be measured
IP intra-train feedback system (Oxford) Last line of defence against relative beam misalignment Measure vertical position of outgoing beam and hence 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 (Oxford) Monitoring of Alignment and Stabilization with high Accuracy to monitor the relative displacement between QD 0 and Shintake monitor at Nanometer 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! eter m e c n a dist MONALISA Retro-reflector Interference pattern sensitive to perpendicular motion of retro-reflector
Cost Breakup, 26 Jan. 07 es pli su p s t r o p p s u r s e t v e o n g m a g m n i d u l c in CF : In po w er mag CF: floor, shield etc. nets Total 5. 7 Oku-yen frastru c ture s l o o t g r n i n o o i t s s i i m n m o co m vac u um l Q-BPMs ro nt co w i re o M a s i l na feed b a c l k a s e r t n i Sh e k a alignment
ATF 2 Schedule Present ATF 2 ON 1. International Construction and Operation; Mini. ILC 2. Forefront of Accelerator Technological R&D 3. Human Resource Development for ILC
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