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Beamline A – Joint Engineering, Environment and Processing Beamline ( JEEP ). Alexander Korsunsky Department of Engineering Science University of Oxford Parks Road, Oxford OX1 3PJ. Acknowledgments :
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Beamline A – Joint Engineering, Environment and Processing Beamline ( JEEP ) Alexander KorsunskyDepartment of Engineering Science University of Oxford Parks Road, Oxford OX1 3PJ Acknowledgments: P.J. Withers, A. Pawley, M. Henderson, P. Barnes, P.J. Webster, D. Laundy, S. Collins, G. Davis, J. Elliott, R. Lewis, M. Daymond and other members of the working group
High energy beamline for general engineering use (JEEP) Another high energy beamline for DIAMOND?
What is a modern engineer? Engineers deal with objects, either designed & manufactured, or naturally occurring, that are intended to perform a certain function in an optimal way. This function is often load bearing. An engineer in this context could be a mechanical or materials specialist, concerned with chemical or deformation processing, or with natural structures such as minerals or our bodies (bio-medical). Engineers share common goals, requirements and methods.
Modern engineer’s ideal tool ? • Non-destructive / non-invasive • Fast and efficient • High contrast and low noise • Spatially resolving down to sub-micron level • Specific to chemical species • Phase specific • Orientation specific
Modern engineer’s ideal tool is a beam • Highly penetrating • Suitably parallel • High flux • Interacting with matter on a variety of scales • Moderately absorbed • Efficiently detectable … a high energy synchrotron X-ray beam!
JEEP: “Synchrotron-assisted engineering“ • Mission: “image and measure in situ real engineering structures” • JEEP will be the first instrument to be truly designed for engineers – will be a world beater • JEEP will offer unprecedented flexibility and range thanks to the two-hutch design philosophy • JEEP‘s sample-centred design will allow installation and use of large scale manipulation and environmental control equipment – that will match the scale of a synchrotron facility for the first time • JEEP will be a truly general purpose – operation mode and beamline optics will be tuned to the sample (physical size, microstructure, grain size, etc.)
Rise of SynchrotronEngineering Research Will synchrotron scanning for engineering continue to double every 3 years?
Percentage of publications on the strain scanning use of synchrotrons
Gauge Volume Compression Tension x y Tension Compression 3D internal mapping By scanning the object very precisely through the gauge volume it is possible to build up 3D maps of the lattice parameter (and hence phase and strain) throughout the object.
TEDDI Tomographic Energy-Dispersive Diffraction Imaging scan of 6×13 mm area inside a a bulk (80 mm. thick) concrete block showing regions of aggregate (calcite, dolomite) and binding cement hydrate (portlandite, ettringite). (Paul Barnes et al. Birkbeck College & SRS)
Multi-phase reactions under high P (A. Pawley, M.Henderson et al., SRS)
Strain scanning The atomic strain gauge - Change in spacing between the rows of atoms is recorded as a shift in the diffraction peaks
Residual stresses in gears Residual stresses are often controlled by processing in order to provide improved durability. Reliable quantification of these effects requires accurate stress mapping. The example shown is the residual stress map in a slice form a gear tooth of a large marine gear (Korsunsky et al., Oxford & SRS, 2002)
Residual stresses in welds and weld process optimisation Welding Torch Filler Wire 2024 Plate Mechanical Constraint
Transverse strain in a TIG weld Synchrotron Synchrotron Model Model Direct FE Validation Longitudinal strain in a TIG weld (P.J.Webster et al, Salford & ESRF)
Linear elastic fracture mechanics Understanding fatigue resistance of structural materials is key to improved durability. Crack tip strain fields can be mapped directly in detail … … and compared with the theoretical predictions of fracture mechanics. (Korsunsky et al., Oxford & ESRF, 2001)
3D image: crack plane in Ti/SiCf composite (P.J.Withers et al., ESRF, 2001)
Diffraction-enhanced imaging (R.Lewis et al., Elettra & SRS)
Refraction Peak of Analyser Image contrast (R.Lewis et al., Elettra & SRS)
Endobon graft (G.R. Davis, J.C. Elliott et al, QM&W)
Of beamline design • Strain scanning was not envisaged on SRS or ESRF before the instruments were built • However, flexibility of the original instrument design (space, beam height, detectors, etc) meant that we could easily exploit the excellent beam characteristics • When designing instruments, make sure short term thinking does not constrain possible future users
Referees’ views • “JEEP will occupy a unique niche between lower energy XRD and neutron diffraction and will bridge the length scales accessible by those techniques” • “It is important to recognise that large sample sizes and associated equipment are key to bridging micro- and macro-scales” • “JEEP will contribute to improved engineering (decreased time-to-application) and improved predictive ability in various areas of science”
Referees’ views • “With ENGIN and JEEP the climate seems right for significant innovation and breakthroughs. At this time, the infrastructure and political will to emphasize engineering are present” • “The engineering studies will complement the time resolved work nicely and will result in tools that will shorten the development cycle” • “It is an area of obvious academic and economic impact” • “The two-hutch design will work and will allow for set-up of complex engineering experiments without interrupting the experimentalists in the first hutch”
Referees’ views • JEEP to ENGIN is like DIAMOND to ISIS • “A compelling reason for locating Diamond at RAL in the first place was the synergy between ISIS and the new synchrotron facility” • “The engineering instrument on DIAMOND will certainly hold a considerable resolution advantage over ISIS. However, a 5 year head start on the ENGIN-X project (to operate in 2003) will provide considerable infrastructure, industrial contacts and personnel expertise on which JEEP beamline can draw” • “The exterior hutch on JEEP (Engnineering Applications Centre) will help coordinate work between ISIS and DIAMOND”
Challenges • A broad mission, built not on a single technique, but on the affinity of discipline(s) • Clear need for strong management procedures to reconcile the different aspects of science to be tackled • Great need for excellent staff to provide technical scientific and computing support • Need for excellent procedures for continuous development and adoption of best optics, detectors and ancillary equipment solutions
The JEEP concept EAC
Hard to focus? • 3rd generation undulators work at well 80keV+ • Divergence: undulator 10020µrad, wiggler 10.2mrad. • Bragg angle at 100keV(Si 111): ~1º– need higher orders? • Darwin width at 100keV (Si 111): ~0.5 arc seconds (decreases with energy) • Mirror critical angle 0.7mrad at 100keV • Sagittal monochromator: R~0.4m at 100keV • Heat loading highest for high field MPWs
Focusing Solutions • Mirrors • collect too small a fan at high energy. Kirkpatrick-Baez? • Multilayers • beam is deflected • bandpass ~ 10-3. Slope errors? • d~100Å: small Bragg angle, need long multilayers • Possible use for vertical focussing where radiation fan is smaller • Bragg • Long crystals + in double bounce beam moves a long way • sagittal bend - up to 60keV with high order reflection • meridional bend deflects beam so fixed wavelength only • Laue
Power of Diamond IDs • Diamond Undulators • Power up to 6 kW • Power density up to 19 kW/mrad/mrad • Diamond MPWs • Power up to 50kW • Power Density 23kW/mrad/mrad • Cornell G Line - 17kW in 1.7mrad
Laue focusing • Near normal incidence means lower heat loading • Integrated reflectivity depends on thickness - more intensity? • Asymmetrically cut crystals (Zhong, Kao, Siddons et al. 2001). • Anti-clastic curvature: lower divergence contrib. to bandpass + vertical focusing • Two crystal arrangement allows fixed offset for tunability Sagittal: 1mradto 0.4mm (NSLS) Meridional: E/E~410-4;1mrad to 0.5mm
Optics and detectors • At present, there is no “off the shelf“ solution • Feasibility study required into sagittal focusing monochromators for SRS (16.3, 16.4, 9.1 etc.) • Further work required on making a bender, understanding dynamical diffraction in distorted crystals, graded crystals. • Possible use of refractive optics? • Detector systems evolve rapidly (eg CCDs) – initial choice will be made in about 24 months • Dual hutch philosophy: choice of resolution vs area available for both beam and detectors
Management • The JEEP project will be managed in the design, construction and operation stages by a panel of experts each championing an engineering application theme • The panel will include two representatives from industry and one liaison member from ISIS • Chair of the panel will rotate annually between theme representatives • The panel will be tasked with maintaining the balance between themes • The panel will advise on optimal experiment scheduling
Development framework • The choice of initial range of detector systems will be based on further research during the next two years • Large scale ancillary equipment will be separately funded and developed within ‘clusters’ of experts which will deliver it for the use by all other users • The outer hutch will provide a special location and unprecedented opportunities for development • Special capabilities will be developed for off-line experiment set-up based on laser coordinate measurement procedures • Availability of the outer hutch will encourage involvement of UK industry in longer term projects
Equipment Optics hutch 2 (outer) Slit/shutters Monochromator/Focussing Experiment hutch 2 (outer) Building (double storey height, crane) Translation Optics hutch 1 (inner) Slits/shutters Monochromator/Focussing Experiment hutch 1 (inner) Kappa diffractometer (e.g. KUMA) Translation/Mini-loadrig/Thermal Theodolites / Laser positioning Detector arrays Cost estimate: £3.5M
Conclusions • JEEP will be a world beater – thanks to clear vision of the objectives and targeted design • JEEP will offer unprecedented flexibility and range thanks to the two-hutch design philosophy • JEEP will be a truly general purpose – operation mode and beamline optics will be tuned to the sample (physical size, microstructure, grain size, etc.) • JEEP will have built-in management and development procedures to ensure rapid adoption of best techniques