Accelerator Physics
Insertion Devices
Magnets
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Open Access
Abstract: At Diamond Light Source we are considering an upgrade of the machine aimed at significantly reduced emittance (la factor 20), that follows a worldwide trend in similar synchrotron radiation sources. An important aspect in the design of the upgrade is the optimization of the photon beam properties, such as flux, brilliance, spot size, divergence or coherence of the new sources and how these are translated into requirements on the electron beam and on the machine design. We present a study based on a combination of accelerator physics tracking codes (AT, elegant) and of radiation codes (SPECTRA, SRW, SHADOW), with the aim at bridging the gap between machine and beamlines.
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Jun 2018
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I13-1-Coherence
Controls
Detectors
Insertion Devices
Magnets
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Open Access
Abstract: Synchrotron radiation provides a number of outstanding features
that are highly valuable for X-ray imaging and tomography. One of
them is the partial coherence of the radiation, which is explored at
the X-ray Imaging and Coherence beamline (I13) at Diamond Light
Source. The variety of methods employed at the beamline offer imaging with the highest quality. We discuss the benefi t of imaging with
coherent radiation and describe methods and applications available at Diamond’s I13 beamline.
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Sep 2017
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Insertion Devices
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Open Access
Abstract: Diamond Light Source is pioneering the move to a
Multi Bend Achromat storage ring lattice for low emittance
combined with the creation of new straight sections
available for Insertion Devices (ID). Diamond is at an
advanced stage of replacing one Double Bend Achromat
(DBA) cell of the existing storage ring with a Double
Double Bend Achromat (DDBA). The DDBA cell which
is to be installed in Autumn 2016 has 4 dipoles and has
been designed with a new straight section in the middle.
This allows ID radiation to shine down an existing Bending
Magnet port in the shield wall for a new micro-focus
protein crystallography beamline called VMX-m. This
same principle will be applied to the proposed Diamond
II project which will be based on a Double Triple Bend
Achromat with 6 dipoles per cell achieving even lower
emittance whilst providing many more IDs. This paper
describes the engineering challenges of these projects.
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Jun 2017
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Insertion Devices
RF
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Open Access
Abstract: The characterisation of the multi-bunch dynamics at the Diamond light source is performed with an advanced TMBF system that is capable of operating fast grow damp experiments thus allowing the exploration of many machine conditions. We report here the latest results of the measurement campaign, the implication on the machine impedance model and some of the intricacies of the analysis and interpretation of the experimental data.
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May 2017
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Insertion Devices
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Open Access
Abstract: Electron beam heating is a widely observed phenomenon at synchrotron facilities around the world, and has a large impact particularly on cryogenic insertion devices, but also on room temperature devices. This paper seeks to outline electron beam heating measurements taken at Diamond Light Source (DLS) and produces an empirical heat load relationship that matches the form of heating through the anomalous skin effect, although gives an order of magnitude higher than that predicted by theory. Resistive wall heating should vary inversely with the gap of installed cryogenic and permanent magnet insertion devices. This is also examined in this paper and the results presented.
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May 2017
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Electrical Engineering
Insertion Devices
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Open Access
Abstract: In planning the upgrade of one cell of the Diamond Storage Ring, the DDBA upgrade, it was evident that the electrical installation and commissioning would contribute a significant component of the overall installation time. Given the pressures to minimise the shutdown length, the electrical and instrumentation design was optimised for time effective installation and commissioning. This paper outlines the electrical and instrumentation design for DDBA; explores the installation time determining issues and how these were addressed; and reports on the lessons learnt from the actual installation and commissioning process.
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May 2017
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Insertion Devices
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Open Access
Abstract: 2017 marks the tenth year of Diamond operation, during which time all insertion device straights have been filled. Diamond Light Source is a third generation, 3 GeV facility that boasts 29 installed insertion devices. Most room temperature devices have been designed, manufactured and measured in-house, and progress has been made in structure design and control systems to ensure new devices continue to meet stringent requirements placed upon them. The ‘completion' of the storage ring is not, however, the end of activity for the ID group at Diamond, as beamlines map out potential upgrade paths to Cryogenic Permanent Magnet Undulators (CPMUs) and SuperConducting Undulators (SCUs). This paper traces the progress of ID design at Diamond, and maps out future projects such as the upgrade to CPMUs and the challenges of designing a fixed-gap mini-wiggler to replace a sextupole in the main storage ring lattice.
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May 2017
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Accelerator Physics
Electrical Engineering
Insertion Devices
Magnets
RF
Theoretical Physics
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Abstract: A simple method, based on layer by layer direct summation, is used to determine the local dipolar fields in uniformly magnetized thin films. The results show that the dipolar constants converge ~1/m where the number of spins in a square film is given by (2m+1)^2. Dipolar field results for sc, bcc, fcc, and hexagonal lattices are presented and discussed. The results can be used to calculate local dipolar fields in films with either ferromagnetic, antiferromagnetic, spiral, exponential decay behavior, provided the magnetic order only changes normal to the film. Differences between the atomistic (local fields) and macroscopic fields (Maxwellian) are also examined. For the latter, the macro B-field inside the film is uniform and falls to zero sharply outside, in accord with Maxwell boundary conditions. In contrast, the local field for the atomistic point dipole model is highly non-linear inside and falls to zero at about three lattice spacing outside the film. Finally, it is argued that the continuum field B (used by the micromagnetic community) and the local field B_loc(r) (used by the FMR community) will lead to differing values for the overall demagnetization energy.
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Aug 2016
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Insertion Devices
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Abstract: I13 is a 250 m long hard x-ray beamline (6 keV to 35 keV) at the Diamond Light Source. The beamline comprises of two independent experimental endstations: one for imaging in direct space using x-ray microscopy and one for imaging in reciprocal space using coherent diffraction based imaging techniques [1]. An outstanding feature of the coherence branch, due to its length and a new generation of ultra-stable beamline instrumentation [2], is its capability of delivering a very large coherence length well beyond 200 μm, providing opportunities for unique x-ray optical experiments. In this paper we discuss the challenges of measuring a large coherence length and present quantitative measurement based on analyzing diffraction patterns from a boron fiber [3]. We also discuss the limitations of this classical method in respect to detector performance, very short and long coherence lengths. Furthermore we demonstrate how a Ronchi grating setup [4] can be used to quickly establish if the beam is coherent over a large area.
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Jul 2016
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Insertion Devices
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Abstract: A major project is underway at Diamond Light Source to remove one of the 24 Double Bend Achromat (DBA) Storage Ring cells and replace it with a Double Double Bend Achromat (DDBA). In this way a new Insertion Device (ID) straight can be created and so ID light can be produced and delivered to a beamline previously only capable of receiving Bending Magnet (BM) radiation. This project is in support of the micro-focus Protein Crystallography (MX) beamline VMX-m which is scheduled to take users towards the end of 2017. This paper describes the Engineering Design of the DDBA project in more detail and gives the current status of the project.
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Jul 2016
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