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Abstract: As the Diamond Light source moves towards upgrading to a 4th generation source, increasing x-ray powers and reduced focal sizes will require improved cryogenic cooling to ensure that the projected new levels of brilliance are achieved. This will create a greater demand for LN2, if current systems are maintained, laying a greater economic demand on the facility. As in most cases, new designs are tested using thermal-structural finite element simulation, neglecting the contribution of fluid flow. This leaves us without information about the effect of the fluid on the surface of the crystal, along with the efficiency of the flow itself. This results in under optimised cooling systems, leaving cooling capabilities of the system reduced, increasing the consumption of LN2. This paper presents a full fluid-structure-thermal model, showing the full effects of the flow of liquid nitrogen on the system. This paper will discuss this model in comparison to a conventional thermal-structure model.

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Abstract: The UK national synchrotron facility, Diamond Light Source, is preparing for a major upgrade to the accelerator complex. Improved beam stability requirements necessitate the fast orbit feedback system be driven from beam position monitors with lower noise and drift performance than the existing solution. Short-term beam motion must be less than 2 nm/sqrt(Hz) over a period of one second with a data rate of 100 kHz, and long-term peak-to-peak beam motion must be less than 1 µm. A new beam position monitor is under development which utilises the pilot-tone correction method to reduce front-end and cabling perturbations to the button signal; and a MicroTCA platform for digital signal processing to provide the required data streams. This paper discusses the challenges faced during the design of the new system and presents experimental results from testing on the existing machine.

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Abstract: The planned Diamond-II storage ring will provide users with an increase in brightness of up to two orders of magnitude compared with the existing Diamond facility. The aim is to maintain excellent photon beam stability in top-up mode, which requires frequent injections. This paper introduces the aperture sharing injection scheme designed for Diamond-II. The scheme promises, through the use of short striplines equipped with high-voltage nano-second pulsers, a quasi-transparent injection while maintaining an approximately 100% injection efficiency.

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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*. 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.

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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.