metrology and pre-alignment of the components of clic in the pacman project s. w. kamugasa, v....
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Metrology and pre-alignment of the components of CLIC in the PACMAN project
S. W. Kamugasa, V. Vlachakis
CLIC Workshop26-30 January 2015
CERN, Geneva, Switzerland
Particle Accelerator Component’s Metrology and Alignment to the Nanometer scale
Project
funded Innovative Doctoral Program, hosted by
Universities & Laboratories:• Cranfield University• ETH Zürich• LAPP• SYMME• University of Sannio• IFIC• TUDELFT• University of Pisa
Industrial Partners:• DMP• Eltos • Etalon A.G.• Hexagon• Metrolab• National Instruments• SigmaPhi• TNO
CLIC alignment challenge Beam size at IP ≈ 40 nm × 1 nm Achievable with beam based alignment Modules pre-alignment: 10 μm / 200 m sliding window
Current pre-alignment strategy1. Fiducialization
2. Alignment of components on common support
3. Alignment of common support in tunnel
LASE
R TR
ACKE
R
LASE
R TR
ACKE
R
20,000 modules
Proposed strategy
Integrate fiducialization and alignment on a common support at the same place and same time
• Reduce build up of systematic and random errors
• Achieve required precision & accuracy
• Requires combination of several technologies
Measure distances Estimate:
3D coordinates + uncertainties Least squares adjustment
Adapt FSI (Frequency Scanning Interferometry)
Multilateration
𝑙 𝑖𝑗
𝑣 𝑖𝑗
𝐹 𝑖
𝑅 𝑗
Y
X
Z
Target 3D position ()
Emitter 3D position ()
distance observation
residual
Developed by Oxford
Absolute distance measurement
Employs second laser to counter drift
Traceability ensured by measurement to gas cell
0.5 µm/m uncertainty (95% CL)
Simultaneous measurements (up to 100 distances)
Absolute Multiline
Abso
lute
Mul
tilin
e by
Eta
lon
AG
Wide viewing angle retroreflector for optimum geometry
Modify fibre end housing to enable absolute distances to be measured
Calibration strategy
Multilateration network
Wire measurement
Simulations
FSI adaptation
Based on Triangulation
• Determines 3D coordinates of geodetic network
• Measures angles (horizontal & vertical)
• Requires distance for scale
Micro-triangulation
• High accuracy industrial theodolites
• Short range measurements
• Few µm precision
Micro-triangulation
Hz
V
Zenith
QDaedalus
• Developed by ETH Zurich Geodesy and Geodynamics lab
• Consists of hardware & software developments
• Replaces eye piece with CCD camera non destructively
• Can reach precision of 10 µm in 3D coordinates
QDaedalus
Optical Target Recognition (OTR)
• Centre of mass
• Template least squares matching
• Circle matching
• Ellipse matching
Advantages of OTR
• Distant, fragile, hot or cold targets can be used
• Relatively cheap targets
• No need to touch targets
• Useful in hazardous environments
Detection algorithms
Micro-triangulation developments
Stretched wire algorithm
• 0.1 mm wire detection (image processing)
• Extraction of angle measurements
• 3D vector reconstruction
Other enhancements
• Hardware
• Software
Conclusion
PACMAN aims:
Tasks:
Y
X
Z
Thank you!