Post on 20-Jan-2016
ATF2ILC Final Focus Test Beam Line
at KEK-ATF
References :
ATF2 Proposal, KEK Report 2005-2
ATF2 Proposal Vol.2, KEK Report 2005-9
ホームページ:
http://atf.kek.jp/collab/ap/projects/ATF2/index.php
110 authors (25 reseach institutes) in the proposal
ATF2 Final GoalEnsure collisions between nanometer beams; i.e. luminosity for ILC
experiment
FACILITYconstructio
n,first result
ATF2/KEK2005-07-08?
FFTB/SLAC1991-93-94
Optics
Local chromaticity correction scheme; very short and longer L*
(β*y=100μm, Ltot=36.6m)
Conventional (separate) scheme; non-local and
dedicated CCS at upstream; high symmetry; i.e.
orthogonal tuning (β*
y=100μm, Ltot=185m)
Design beam size
34nm / 2.2μm, aspect=65
(γεy=3 x 10-8 m)
60nm / 1.92μm, aspect=32
(γεy=2 x 10-6 m)
Achieved ?70nm ( beam jitter remains !)
Reduction of Risk at ILCOptics and bean tuningStabilization
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 2006
6m
reduction of dispersion
final focus
diagnostic
west テキスト
ATF2 beam line and ATF extraction line
ATF2 beam line ATF extraction line
ATF2 beam line and ATF extraction line
5 Wire Scanners or Laserwires5 Strip-line
BPMs
3 Screen Monitors
BSM
CLIC table
HVVHV
5 Steering (V,H) Magnets
SF5
H
53 m
22 Quadrupoles(Q), 5 Sextupoles(S), 3 Bends(B) in downstream of QM16
QM16
SD4 SF6B5B2B1QD0 QF1
SD0SF1
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 IPMONALISA ( nanometer alignment monitor with laser interferometer )Laserwire ( beam size monitor with laser beam )IP intra-train feedback system with latency of less than 150nsMagnet 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
SF6
SF5
SD4
SF1
SD0
B1B2
B5
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 bend200ms
ΔB=-100GB=3.1kG
Voltage
Test result with 3+1 system (150A)switch off 1 module
short time : 2-3ppmlong time : 5ppmtemperature : 2.5ppm/℃
A.Jeremie
Bloc:61
Foot:26.5
Total:87.5
Length:240Width: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 PipeSlot
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
14 cm
(61.45 x 48.58 x 6mm3)
(6 x 12 mm2)
Goal : 2nm position resolution
Residual vs TimeResidual of (Y2I – Y2Ipredicted)
1h
Preliminary beam test result :
Position resolution for 1 hour run
8.72 +- 0.28 (stat.) +- 0.35 (sys.) nm
( ICT = 0.68 x 1010 e-/bunch,
dynamic range = 4.96 um )
(KEK, KNU)
Schematics of Shintake MonitorMeasure beam size using phase (=position and period) of interference fringe
as a reference
Interference fringesas a reference
Electron beamto be measured
Scanning electron beam
γ-ray modulatedby 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
suppor
ts
includ
ing
moversalignmen
tvacuumcontrol
feedbac
kQ-BPMslaserwireShi
ntake
monito
r
CF :Infrastructure
CF:floor,shield etc.
Total 5.7 Oku-yen
commission
ing
tools
Monalis
a
ATF2 SchedulePresent ATF2 ON
1. International Construction and Operation; Mini-ILC 2. Forefront of Accelerator Technological R&D3. Human Resource Development for ILC4. Commissioning in October 2008