Mechanical Engineering
Optics
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Abstract: Every mirror at Diamond Light Source (the UK's Particle Accelerator) has been installed with the premise of clamping the cooling copper manifolds as lightly as possible to minimize distortion. The problem with this approach is that the Thermal Contact Conductance (TCC) depends on the applied pressure among other factors like surface Flatness, Waviness, Roughness, Cleanliness, the effects of Oxides, Interstitial material like air or vacuum at the microscopic level or the addition of materials that are used to fill these gaps like grease, coatings, foils as well as the material properties like the Young's Modulus, the Coefficient of Thermal Expansion, the Thermal Conductivity, the Yield Strength and the Temperature at the interface1. The aim of this project is to shed some light on to what thermal contact conductance there is at the interfaces in a typical mirror assembly and aims to gain a deeper understanding about the factors that are under control once everything is fully assembled. The assembly is usually a symmetric stack of Copper - Indium Foil - Silicon Crystal - Indium Foil - Copper. Variables that interest the most are those that are easily adjustable in the set-up assembly (number of clamps, pressure applied and cooling water flow rate) PT100 temperature sensors have been used along the surface of the crystal and along the surface of the copper manifolds. Custom PCB units have been created for this project to act as a mean of collecting data and Matlab has been used to plot the temperature measurements vs. time. Another challenge is the creation of an accurate model in Ansys that matches reality up to a good compromise where the data that is being recorded from the sensors matches Ansys results within reason. Using Ansys software an iterative analysis is performed using a Response Surface Optimization in order to find out the TCC on every scenario. This Thesis has been structured in three parts: Introduction: Explains briefly how a Particle Accelerator works, describes the set-up of a typical Silicon Crystal assembly and aims for gaining a deeper understanding of what is known about the Thermal Contact Conductance. Analysis: Describes how the project has been done from concept through to completion, shows in detail all the tasks carried out at every stage, calculations, assumptions and results. Conclusions: Gathers all the outcomes found during this project, gives a guidance to create an Ansys model that is able to predict the Thermal Contact Conductance with a good repeatability for every scenario and shares key points to bear in mind when dealing with TCC, Friction, Pressure and Heat Transfer.
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Nov 2020
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Mechanical Engineering
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Open Access
Abstract: Experimental Modal Analysis was performed on an existing 5 degree of freedom mirror system on beamline I08 at The Diamond Light Source, by impacting the structure and measuring the response at locations of interest. Commercial software was used to generate the frequency response functions and mode shape animations. This experimental information was used to inform and optimise a design iteration for a new mirror system. The new mechanism was designed, installed and tested on the J08 branch line at The Diamond Light Source to validate the expected improvements in stability, stiffness and resonant frequency. The mirror system fundamental resonant frequency was significantly increased from 20 Hz to 49 Hz.
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Dec 2018
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Mechanical Engineering
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Open Access
Abstract: A common procurement strategy is to produce a fully optimised reference design that makes assumptions about the manufacturing process and supplier capability. This approach can restrict the opportunities for some companies to include their own specialist manufacturing capability to provide a more effective and cost efficient solution. A new approach is suggested following the recent experience at Diamond Light Source. The manufacture of high stiffness welded fabrications up to 13m in length for the I21 RIXS Spectrometer is used as an example. The I21 RIXS Spectrometer design was optimised for stiffness and control of vibration. The use of Finite Element Analysis enabled different design options and compromises to be explored utilising the supplier's capabilities. The final design was tested during manufacture to verify the FEA model. With the I21 RIXS Spectrometer commissioned the data collected shows the final stability performance of the system including detector stability over full experiment durations has met the scientific goals of the design.
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Dec 2018
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Mechanical Engineering
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Open Access
Abstract: The continued increase in the number of Light Sources, their beamlines and the need for upgrades of both machine and beamlines requires an ever larger supply of suitably qualified and experienced engineers. If there is a world wide shortage of Engineers where will facilities find these engineers and how can they be trained to the required level? This paper discusses these issues by looking at the growth of demand for engineers within light sources, the evidence of shortages of engineers, the changes in attitudes to work by younger people, the skills necessary, training opportunities and the issues in attracting people into the light sources industry. The paper will also outline the training week for early career engineers delivered at Diamond.
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Dec 2018
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Electrical Engineering
Magnets
Mechanical Engineering
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Open Access
Abstract: Now that all of the original straight sections in the Diamond storage ring are occupied, novel ways of converting bending magnet beamline locations into insertion device beamlines have been considered. Recently one cell of the 24 cells was reconfigured in to a Double-Double Bend Achromat (DDBA) to provide a new location for an Undulator and enable a formerly designated bending magnet beamline to become an Insertion Device Beamline*. Extending this concept for the new Dual Imaging and Diffraction (DIAD) Beamline proved to have a strong impact on lifetime and injection efficiency, so instead it was decided to remove a Sextupole magnet in one cell and substitute it with a short fixed gap Wiggler. The accelerator physics, mechanical and electrical design aspects associated with the change are described.
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Dec 2018
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Mechanical Engineering
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Open Access
Abstract: Synchrotron facilities play a key part in the delivery of world leading science to facilitate research and development across multiple fields. The enabling technology designed by engineers at these facilities is crucial to their success. The highly academic nature of Synchrotron facilities does not always lead to working in the same way as a commercial engineering company. However, are the engineering requirements at Synchrotrons different to commercial companies? Exploring the parallels between research and commercial companies, can we show that the tools and methodologies employed could benefit engineering development at Synchrotrons? This paper provides a theoretical discussion on the commonality between engineering developments at Synchrotron facilities compared to commercial companies. How methodologies such as Design for Six Sigma and in particular tools such as stakeholder analysis, functional tree analysis, FMEA and DoE could be utilised in the design process at Synchrotrons. It also seeks to demonstrate how implementation could aid the development of innovative, robust and efficient design of engineering solutions to meet the ever-increasing demands of our facilities.
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Dec 2018
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Electrical Engineering
Mechanical Engineering
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Open Access
Abstract: I12 is a high-energy imaging, diffraction and scattering beamline at Diamond. Its source is a superconducting wiggler with a power of approximately 9kW at 500 mA after the fixed front-end aperture; two permanent filters aim at reducing the power in photons below the operating range of the beamline of 50-150 keV, which accounts for about two-thirds of the total*. This paper focuses on the design and simulation process of the secondary permanent filter, a 4mm thick SiC disk. The first version of the filter was vulnerable to cracking due to thermally induced stress, so a new filter based on an innovative concept was proposed: a water-cooled shaft rotates, via a ceramic interface, the SiC disk; the disk operates up to 900 degrees C, and a copper absorber surrounding the filter dissipates the heat through radiation. We utilised analysis data following failure of an initial prototype to successfully model the heat flow using FEA. This model informed different iterations of the re-design of the assembly, addressing the issues identified. The operational temperature of the final product matches within a few degrees C the one predicted by the simulation.
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Dec 2018
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Electrical Engineering
Mechanical Engineering
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Open Access
Abstract: Diamond Light Source is in the process of reviewing several lattice options for a potential storage ring upgrade. As part of these studies, it has become clear that a substantial reduction in emittance can be achieved by adopting an on-axis injection scheme, thereby relaxing the constraints on the dynamic aperture. In order to achieve the necessary injected bunch properties for this to be viable, a new accumulator ring would be needed. In this paper we review the requirements placed on the accumulator ring design, describe the lattice development process and analyse the performance of the initial, conceptual design.
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Sep 2018
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Diagnostics
Magnets
Mechanical Engineering
Optics
Vacuum
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R.
Bartolini
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C.
Abraham
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M.
Apollonio
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C. P.
Bailey
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M. P.
Cox
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A.
Day
,
R. T.
Fielder
,
N. P.
Hammond
,
M. T.
Heron
,
R.
Holdsworth
,
J.
Kay
,
I. P. S.
Martin
,
S.
Mhaskar
,
A.
Miller
,
T.
Pulampong
,
G.
Rehm
,
E. C. M.
Rial
,
A.
Rose
,
A.
Shahveh
,
B.
Singh
,
A.
Thomson
,
R. P.
Walker
Open Access
Abstract: Diamond has recently successfully commissioned a major change in the lattice consisting of the substitution of a standard double-bend achromat (DBA) cell with a modified four-bend achromat (4BA) cell called “double-double bend achromat” (DDBA). This work stems from the original studies initiated in 2012 towards a Diamond upgrade and provides the benefit of an additional straight section in the ring available for insertion devices. This paper reviews the DDBA design and layout, the implications for technical subsystems, the associated engineering challenges and the main results of the commissioning completed in April 2017.
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May 2018
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I19-Small Molecule Single Crystal Diffraction
Mechanical Engineering
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David R.
Allan
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Harriott
Nowell
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Sarah A.
Barnett
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Mark R.
Warren
,
Adrian
Wilcox
,
Jeppe
Christensen
,
Lucy
Saunders
,
Andrew
Peach
,
Mark T.
Hooper
,
Ljubo
Zaja
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Suren
Patel
,
Leo
Cahill
,
Russell
Marshall
,
Steven
Trimnell
,
Andrew
Foster
,
Trevor
Bates
,
Simon
Lay
,
Mark A.
Williams
,
Paul V.
Hathaway
,
Graeme
Winter
,
Markus
Gerstel
,
Ron
Wooley
Open Access
Abstract: Herein, we describe the development of a novel dual air-bearing fixed-χ diffractometer for beamline I19 at Diamond Light Source. The diffractometer is designed to facilitate the rapid data collections possible with a Dectris Pilatus 2M pixel-array photon-counting detector, while allowing remote operation in conjunction with a robotic sample changer. The sphere-of-confusion is made as small as practicably possible, through the use of air-bearings for both the ω and φ axes. The design and construction of the new instrument is described in detail and an accompanying paper by Johnson et al. (also in this issue) will provide a user perspective of its operation.
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Nov 2017
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