Browsing by Author "Sanz, Claude"

Now showing 1 - 6 of 6
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    Characterisation and measurement to the sub-micron scale of a reference wire position
    (EDP Sciences, 2015-09-21) Sanz, Claude; Cherif, Ahmed; Mainaud-Durand, Hélène; Morantz, Paul; Shore, Paul
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    Evaluation of the performance variation of porous air pads on discontinuous surfaces
    (Elsevier, 2019-10-31) Sanz, Claude; Morantz, Paul; Lunt, Alexander J. G.; Shore, Paul; Chérif, Ahmed; Schneider, Jürgen; Mainaud-Durand, Hélène; Steffens, Norbert
    A new high accuracy position measurement system has been developed. It measures the position of a 0.1 mm diameter copper-beryllium wire that informs alignment of energy beams in advanced particle accelerators. This new measurement system employs air pads to provide precision and friction free rotation of a sensor. To enable the measuring system to be positioned over the wire, a slot is required in the measuring device rotor. To optimise the design of this measuring system it was necessary to understand the performance of the air pads as they pass over the gaps (slots) in the rotor. This paper describes modelling and experiments that were performed to gain understanding of air pad performance when encountering such a surface gap. Particularly, an analytical model of the variation of load of a 20 mm × 40 mm porous air pad during the passing of a 1.5 mm wide slotted surface. Subsequent experimentation revealed that the general behaviour of the load variation had been captured effectively. The results of this analysis reveal that air pads of this size can reliably pass above an opening of this size with about 14% reduction in force. The results and the methodology presented in this paper can be used as an effective basis for future designs and studies
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    Form measurement of a 0.1 mm diameter wire with a chromatic confocal sensor, with associated uncertainty evaluation
    (IOP Publishing, 2018-06-07) Sanz, Claude; Giusca, Claudiu; Morantz, Paul; Marin, Antonio; Chérif, Ahmed; Schneider, Jürgen; Mainaud-Durand, Hélène; Shore, Paul; Steffens, Norbert
    The accurate characterisation of a copper–beryllium wire with a diameter of 0.1 mm is one of the steps to increase the precision of future accelerators' pre-alignment. Novelties in measuring the wire properties were found in order to overcome the difficulties brought by its small size. This paper focuses on an implementation of a chromatic-confocal sensor leading to a sub-micrometric uncertainty on the form measurements. Hence, this text reveals a high-accuracy metrology technique applicable to objects with small diameters: it details the methodology, describes a validation by comparison with a reference and specifies the uncertainty budget of this technique.
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    Micro-scale finishing of the surface and form of a Ti-6Al-4V lightweight rotor obtained by laser powder bed fusion used for air bearing
    (Elsevier, 2018-07-26) Sanz, Claude; Gerard, Romain; Morantz, Paul; Chérif, Ahmed; Shore, Paul; Mainaud-Durand, Hélène; Lunt, Alexander J. G.
    The European Organisation for Nuclear Research, CERN, is in the process of designing and testing parts for the next generation of linear accelerators. In order to operate the experiments, the pre-alignment precision of the components of the two opposing accelerating complexes has placed increased demands on part tolerances, which are now approaching the micrometre. In order to meet these demanding requirements, improvements are necessary to the build processes, machining parameters and post-manufacture characterisation stages. One of the most promising methods for the production of these parts is Laser Powder Bed Fusion, and as such, this paper focuses on the manufacture of the lightweight air bearing rotor component and the micro-scale tolerance machining required by this part. The results demonstrate that despite being able to initially machine the part to a form tolerance approaching 2 μm, subsequent notch cutting and the release of residual stresses from the part obtained by Laser Powder Bed Fusion induces an 18 μm part misalignment which is larger than the tolerance limits of 5 μm required for operation. This demonstrates that further minimisation and understanding of the residual stresses induced during machining are required to facilitate the effective manufacture of high precision components of this type.
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    New potential for the Leitz Infinity Coordinate Measuring Machine
    (Euspen, 2015-06-01) Sanz, Claude; Cherif, Ahmed; Mainaud-Durand, Hélène; Schneider, Jürgen; Steffens, Norbert; Morantz, Paul; Shore, Paul
    The following study is realised within the frame of the PACMAN project: a study on Particle Accelerator Components Metrology and Alignment to the Nanometre scale, which is a Marie Curie program supported by the European commission and hosted by CERN (European Organisation for Nuclear Research). The aim of this program is to develop and build a pre-alignment bench on which each component is aligned to the required level in one single step using a stretched wire. During the operation, the centre of the stretched wire is aligned with the magnetic axis of the magnet. Then, the position of the wire is measured to the highest possible accuracy using a 3D Coordinate Measuring Machine (CMM) Leitz PMM-C Infinity from HEXAGON Metrology. The research described in this paper is two-fold: on one hand we apply a strong magnetic field to the head of the CMM and evaluate its influence on the measurement accuracy; on the other hand we measure the position
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    Rotary mount design for a chromatic confocal sensor, involving additive manufacturing and an opened air bearing
    (Cranfield University, 2018-02) Sanz, Claude; Giusca, Claudiu; Morantz, Paul; Shore, Paul
    In 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 contribution