Giusca, ClaudiuMorantz, PaulShore, PaulSanz, Claude2024-08-292024-08-292018-02https://dspace.lib.cranfield.ac.uk/handle/1826/22865Shore, Paul - Associate SupervisorIn the field of high energy physics, the characterisation and positioning in space of a wire with a diameter of 0.1 mm is one of the steps to increase the precision of future accelerators’ pre-alignment. This reference wire is measured within a high accuracy Coordinate Measuring Machine (CMM) to reduce its positioning uncertainty. No sensor could measure the wire position within the targeted uncertainty. This thesis addresses this issue by proposing a design for the Shape Evaluating Sensor: High Accuracy & Touchless (SESHAT). The SESHAT operates a chromatic confocal sensor. The sensor is fixed to a rotor with a radial opening to allow the stretched wire to traverse it. This rotor is guided by a high precision air bearing controlled by a piezoelectric actuator. The mass limit for the stylus system of the CMM entailed the additive manufacturing of a hollow rotor. The high likelihood of particles on the wire surface involved a form deviation capability for the SESHAT, to reduce position measurement uncertainty. The aim of the research was to design a sensor enabling the Leitz Infinity CMM to perform non-contact form measurement on the PACMAN reference wire to permit its axis positioning with an uncertainty such that 3σ < 0.5 µm. The novelty emphasised in this thesis is focused on three main contributions. The form measurement uncertainty reduction obtained by using a chromatic confocal sensor for non-contact measurement on a wire surface is the first contribution. A mathematical model describing the behaviour of air pads over a through hole in the bearing surface composes the second contribution to knowledge. The demonstrated ability to obtain a micrometric form deviation on a rotary symmetric complex shape generated by additive manufacturing of titanium is the third contributionen© Cranfield University, 2018. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.Metrology toolHigh Precision MechanicsReferenceAlignmentParticle AcceleratorCompact Linear Collider CLICCoordinate Measuring MachineEuropean Centre for Nuclear Research CERNThesis