IPAC2016 - List of Authors (Sosin, M.)

Paper	Title	Page
WEPOR017	A Micrometric Positioning Sensor for Laser-Based Alignment	2700
	G. Stern, H. Mainaud Durand, D. Piedigrossi, M. Sosin CERN, Geneva, Switzerland A. Geiger, S. Guillaume ETH, Zurich, Switzerland
	The Compact Linear Collider requires 10 μm accuracy over 200m for the alignment of its components. Since current techniques based on stretched wire or water level are difficult to implement, other options are under study. We propose a laser alignment system using positioning sensors made of camera/shutter assemblies. The goal is to implement such a positioning sensor. The corresponding studies comprise design and calibration as well as investigations of measurement accuracy and precision. On the one hand, we describe mathematically the laser beam propagation, its interaction with the shutter and image processing. On the other hand, we present experiments done with the prototype of a positioning sensor. As a result, we give practical suggestions to build the positioning sensors and we describe a calibration protocol to be applied to all sensors before measuring. In addition, we deliver estimates for measurement accuracy and precision. Our work provides the first steps towards a full alignment system.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR017
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WEPOR018	Position Monitoring System for HL-LHC Crab Cavities	2704
	M. Sosin, T. Dijoud, H. Mainaud Durand CERN, Geneva, Switzerland V. Rude ESGT-CNAM, Le Mans, France
	The high luminosity upgrade for the LHC at CERN (HL-LHC project) will extend the discovery potential of the LHC by a factor 10. It relies on key innovative technologies like superconducting cavities for beam rotation, named 'crab cavities'. Two crab cavities will be hosted in a superconducting cryostat working at a cold (<3 K). The position of each cavity will be monitored during the cool-down and the operation in order to comply with the tight alignment tolerances: the misalignment of a cavity axis w.r.t. the other will have to be lower than 0.5 mm and each cavity roll w.r.t. the cryostat axis will have to be lower than 1 mrad. Moreover, the monitoring system will have to be radiation hard (up to 10 MGy) and maintenance free. We propose a solution based on the Frequency Scanning Interferometry to provide the position monitoring of the crab cavities. This paper describes the design and study of such a solution, including the engineering approach, the issues encountered and the lessons learnt.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR018
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THPOR033	Integration and Testing of 3 Consecutive CLIC Two-Beam Modules	3856
	A.L. Vamvakas, M. Aicheler, S. Döbert, M. Duquenne, H.M. Durand, M. Sosin, J.I. Väinölä CERN, Geneva, Switzerland V. Rude ESGT-CNAM, Le Mans, France
	CLIC (Compact LInear Collider) is a study of a 50 km long linear electron-positron collider, consisting of ap-proximately 20,000 repetitive 2 m long modules. Micron level manufacturing and alignment tolerances are re-quired for the RF and magnet components due to the nanometre beam size and luminosity goal. The effect of thermal, vacuum and mechanical loads needs to be as-sessed, both in transient and in steady state conditions. The dynamic behaviour of mock-ups was investigated on the prototype two-beam module. Two additional two-beam modules are installed to further investigate the interconnections between them, in a machine-like envi-ronment. The array of three consecutive modules allows for alignment tests of the module sequence, while thermal and vacuum tests can be executed simultaneously. A transportation experiment is foreseen, investigating the feasibility of installing prealigned modules. Finally, new design of components is being tested, based on the expe-rience gathered from the first module and leading to a new generation module.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR033
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

A Micrometric Positioning Sensor for Laser-Based Alignment

2700

G. Stern, H. Mainaud Durand, D. Piedigrossi, M. Sosin
CERN, Geneva, Switzerland
A. Geiger, S. Guillaume
ETH, Zurich, Switzerland

The Compact Linear Collider requires 10 μm accuracy over 200m for the alignment of its components. Since current techniques based on stretched wire or water level are difficult to implement, other options are under study. We propose a laser alignment system using positioning sensors made of camera/shutter assemblies. The goal is to implement such a positioning sensor. The corresponding studies comprise design and calibration as well as investigations of measurement accuracy and precision. On the one hand, we describe mathematically the laser beam propagation, its interaction with the shutter and image processing. On the other hand, we present experiments done with the prototype of a positioning sensor. As a result, we give practical suggestions to build the positioning sensors and we describe a calibration protocol to be applied to all sensors before measuring. In addition, we deliver estimates for measurement accuracy and precision. Our work provides the first steps towards a full alignment system.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR017

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOR018

Position Monitoring System for HL-LHC Crab Cavities

2704

M. Sosin, T. Dijoud, H. Mainaud Durand
CERN, Geneva, Switzerland
V. Rude
ESGT-CNAM, Le Mans, France

The high luminosity upgrade for the LHC at CERN (HL-LHC project) will extend the discovery potential of the LHC by a factor 10. It relies on key innovative technologies like superconducting cavities for beam rotation, named 'crab cavities'. Two crab cavities will be hosted in a superconducting cryostat working at a cold (<3 K). The position of each cavity will be monitored during the cool-down and the operation in order to comply with the tight alignment tolerances: the misalignment of a cavity axis w.r.t. the other will have to be lower than 0.5 mm and each cavity roll w.r.t. the cryostat axis will have to be lower than 1 mrad. Moreover, the monitoring system will have to be radiation hard (up to 10 MGy) and maintenance free. We propose a solution based on the Frequency Scanning Interferometry to provide the position monitoring of the crab cavities. This paper describes the design and study of such a solution, including the engineering approach, the issues encountered and the lessons learnt.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR018

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOR033

Integration and Testing of 3 Consecutive CLIC Two-Beam Modules

3856

A.L. Vamvakas, M. Aicheler, S. Döbert, M. Duquenne, H.M. Durand, M. Sosin, J.I. Väinölä
CERN, Geneva, Switzerland
V. Rude
ESGT-CNAM, Le Mans, France

CLIC (Compact LInear Collider) is a study of a 50 km long linear electron-positron collider, consisting of ap-proximately 20,000 repetitive 2 m long modules. Micron level manufacturing and alignment tolerances are re-quired for the RF and magnet components due to the nanometre beam size and luminosity goal. The effect of thermal, vacuum and mechanical loads needs to be as-sessed, both in transient and in steady state conditions. The dynamic behaviour of mock-ups was investigated on the prototype two-beam module. Two additional two-beam modules are installed to further investigate the interconnections between them, in a machine-like envi-ronment. The array of three consecutive modules allows for alignment tests of the module sequence, while thermal and vacuum tests can be executed simultaneously. A transportation experiment is foreseen, investigating the feasibility of installing prealigned modules. Finally, new design of components is being tested, based on the expe-rience gathered from the first module and leading to a new generation module.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR033

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