MEDSI2018 - List of Keywords (feedback)

Paper	Title	Other Keywords	Page
WEOAMA02	Sample Stabilization for Tomography Experiments in Presence of Large Plant Uncertainty	controls, experiment, SRF, simulation	153
	T. Dehaeze, C.G.R.L. Collette PML, Liège, Belgium C.G.R.L. Collette ULB - FSA - SMN, Bruxelles, Belgium T. Dehaeze, M. Magnin-Mattenet ESRF, Grenoble, France
	A new low emittance lattice storage ring is under construction at the ESRF. In this new instrument, an upgraded end station for ID31 beamline must allow to position the samples along complex trajectories with a nanometer precision. In order to reach these requirements, samples have to be mounted on high precision stages, combining a capability of large stroke, spin motion, and active rejection of disturbances. First, the end station will be presented with the associated requirements. However, the precision is limited by thermal expansion and various imperfections that are not actively compensated. Our approach is to add a Nano Active Stabilization System (NASS) which is composed of a 6DoF Stewart platform and a 6 DoF metrology system. A 3D model of the end station updated with experimental data is developed. As the mass of the samples may vary by up to two orders of magnitudes, robust control strategies are required to address such plant uncertainty. The proposed control strategy are presented and applied on the developed model by conducting time domain simulations of tomography experiment in presence of instrumentation noise and system uncertainty.
	Slides WEOAMA02 [1.721 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-WEOAMA02
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WEOAMA04	The Design of Exactly-Constrained X-Ray Mirror Systems for Sirius	vacuum, alignment, operation, coupling	173
	R.R. Geraldes, G.V. Claudiano, V.Z. Ferreira, L. Sanfelici, A. Sikorski, M.S. Souza, H.C.N. Tolentino, L.M. Volpe, H. Westfahl Jr. LNLS, Campinas, Brazil
	Funding: Ministry of Science, Technology, Innovation and Communication (MCTIC) The first set of Sirius beamlines is expected to start operating in early 2019. Regarding X-ray mirror sys-tems, a single design concept has been possible thanks to the standardization of side-bounce fixed-shape mirrors. To preserve the extreme quality of both the mirror figures and the source, the main design targets were minimizing mechanical and thermal distortions in the mirrors while maximizing mechanical and thermal stabilities. A deterministic high-resolution exactly-constrained flexure-based mirror support provides pitch tuning within 100 nrad and resonances above 150 Hz, while dealing with clamping and thermal ex-pansion effects. The adopted cooling strategy was indirect cryocooling via cryostats, drastically minimiz-ing thermal gradients and distortions in the mirrors, decoupling vibration sources and simplifying cooling circuits. Finally, a 5-degree-of-freedom granite bench, based on high-resolution levellers and air-bearing solutions, support the vacuum chamber, on which the internal mechanics is stiffly mounted. The specifica-tions, design and partial results are presented.
	Slides WEOAMA04 [6.607 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-WEOAMA04
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPH04	Fast X-Ray Beam Intensity Stabilization for Absorption Spectroscopy and Spectromicroscopic Imaging	controls, focusing, vacuum, photon	343
	M. Birri, D. Ferreira Sanchez, D. Grolimund, B. Meyer, V.A. Samson PSI, Villigen PSI, Switzerland
	The characteristics of synchrotron sources and beamline optics commonly result in systematic and random variations of the delivered photon flux. In X-ray absorption based measurements, for example, monochromator glitches [1] or the energy dependent gap size of small gap in-vacuum undulators [2] are intrinsic sources for changes in the intensity of the incoming photon flux (I0), however many types of x-ray experiments would benefit from a constant I0. Monochromator Stabilization (MOSTAB) is a common solution for most synchrotron beamlines with double crystal monochromators. This approach is based on the relative alignment of the two monochromator crystals (dynamic detuning) to stabilize beam intensity or position. Obviously, any change in angular alignment of the monochromator crystals will also induce deviations in the beam trajectory and photon energy distribution. At the microXAS undulator beamline of the SLS, we have implemented a system to achieve a constant I0. Two wedge-shaped absorbers produce a spatially uniform attenuation preserving the beam shape without introducing changes in its trajectory. Hardware, control loop and system performance will be presented. [1] F.Bridges, Nuclear Instruments and Methods in Physics Research A257 (1987) 447-450. [2] H.Kitamura, J.Synchrotron Rad. 7 (2000), 121-130.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-THPH04
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THPH15	A New High Precision, Fully Motorized 6-DoF Sample Stage for the ALBA PEEM Endstation	GUI, controls, resonance, vacuum	368
	N. Gonzalez, L. Aballe, A. Carballedo, C. Colldelram, M. Foerster ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	A new 6-DOF sample manipulator has been designed for the ALBA Synchrotron PhotoEmission Electron Microscopy (PEEM) experimental station, based on a commercial Elmitec LEEM 3. The new design includes full motorization of all 6 axes with position feedback, no backlash, and maximized stability, crucial to achieve the best spatial resolution of down to 8 nm (in so-called LEEM mode). The in-plane longitudinal and transversal motions with sub-micron resolution are based on high precision linear guides, while the pitch and roll stages (sample tilt), guided by angular guides, are actuated by a double-flexure system, which enhances the overall rigidity of the system. The vertical stage is composed by a high rigidity recirculating roller screw and cross roller guides. Finally, 360° yaw rotation is supplied by a differentially pumped commercial rotary stage. On top of the stage, the sample support is mounted on a customized DN63CF flange. This support keeps the original functionalities of the sample manipulator and holders, with 6 independent electrical contacts, and the possibility to heat the sample up to 2000 K and cool it to 100 K with an improved liquid nitrogen cooling system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-THPH15
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THPH16	Compact Mirror Bender With Sub-Nanometer Adaptive Correction Control	optics, controls, synchrotron, focusing	371
	N. Gonzalez, C. Colldelram, J.B. González Fernández, J. Juanhuix, J. Nicolás, C. Ruget ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	Funding: This work is partially funded by MINECO under contract FIS2015-66328-C3-2-R and by ERDF funds. We present a compact mirror bender with dynamic surface correction. The system is the evolution of an in-house development and will be the default focusing system for the new ALBA beamlines. The bender is now more compact and can introduce stronger curvatures, as required for microfocus applications. It allows for in-situ correction of the mirror surface, with resolution and stability below one nanometer. The bender can compensate parasitic deformations caused by thermal bumps, changes of focus, or stresses appeared during installation or bakeout. The system includes two torque actuators at the ends of the mirror as well as a number of correctors along the mirror length, capable of introducing high order surface corrections. The bending curvature is actively stabilized, by a feedback loop that controls the applied force, to the equivalent of 0.25 nm rms in a 500 mm long mirror. The figure correctors provide up to 20N push-pull force with resolution below .001 N. They combine elastic and magnetic forces to improve their stability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-THPH16
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

WEOAMA02

Sample Stabilization for Tomography Experiments in Presence of Large Plant Uncertainty

controls, experiment, SRF, simulation

153

T. Dehaeze, C.G.R.L. Collette
PML, Liège, Belgium
C.G.R.L. Collette
ULB - FSA - SMN, Bruxelles, Belgium
T. Dehaeze, M. Magnin-Mattenet
ESRF, Grenoble, France

A new low emittance lattice storage ring is under construction at the ESRF. In this new instrument, an upgraded end station for ID31 beamline must allow to position the samples along complex trajectories with a nanometer precision. In order to reach these requirements, samples have to be mounted on high precision stages, combining a capability of large stroke, spin motion, and active rejection of disturbances. First, the end station will be presented with the associated requirements. However, the precision is limited by thermal expansion and various imperfections that are not actively compensated. Our approach is to add a Nano Active Stabilization System (NASS) which is composed of a 6DoF Stewart platform and a 6 DoF metrology system. A 3D model of the end station updated with experimental data is developed. As the mass of the samples may vary by up to two orders of magnitudes, robust control strategies are required to address such plant uncertainty. The proposed control strategy are presented and applied on the developed model by conducting time domain simulations of tomography experiment in presence of instrumentation noise and system uncertainty.

Slides WEOAMA02 [1.721 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-WEOAMA02

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEOAMA04

The Design of Exactly-Constrained X-Ray Mirror Systems for Sirius

vacuum, alignment, operation, coupling

173

R.R. Geraldes, G.V. Claudiano, V.Z. Ferreira, L. Sanfelici, A. Sikorski, M.S. Souza, H.C.N. Tolentino, L.M. Volpe, H. Westfahl Jr.
LNLS, Campinas, Brazil

Funding: Ministry of Science, Technology, Innovation and Communication (MCTIC)
The first set of Sirius beamlines is expected to start operating in early 2019. Regarding X-ray mirror sys-tems, a single design concept has been possible thanks to the standardization of side-bounce fixed-shape mirrors. To preserve the extreme quality of both the mirror figures and the source, the main design targets were minimizing mechanical and thermal distortions in the mirrors while maximizing mechanical and thermal stabilities. A deterministic high-resolution exactly-constrained flexure-based mirror support provides pitch tuning within 100 nrad and resonances above 150 Hz, while dealing with clamping and thermal ex-pansion effects. The adopted cooling strategy was indirect cryocooling via cryostats, drastically minimiz-ing thermal gradients and distortions in the mirrors, decoupling vibration sources and simplifying cooling circuits. Finally, a 5-degree-of-freedom granite bench, based on high-resolution levellers and air-bearing solutions, support the vacuum chamber, on which the internal mechanics is stiffly mounted. The specifica-tions, design and partial results are presented.

Slides WEOAMA04 [6.607 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-WEOAMA04

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPH04

Fast X-Ray Beam Intensity Stabilization for Absorption Spectroscopy and Spectromicroscopic Imaging

controls, focusing, vacuum, photon

343

M. Birri, D. Ferreira Sanchez, D. Grolimund, B. Meyer, V.A. Samson
PSI, Villigen PSI, Switzerland

The characteristics of synchrotron sources and beamline optics commonly result in systematic and random variations of the delivered photon flux. In X-ray absorption based measurements, for example, monochromator glitches [1] or the energy dependent gap size of small gap in-vacuum undulators [2] are intrinsic sources for changes in the intensity of the incoming photon flux (I0), however many types of x-ray experiments would benefit from a constant I0. Monochromator Stabilization (MOSTAB) is a common solution for most synchrotron beamlines with double crystal monochromators. This approach is based on the relative alignment of the two monochromator crystals (dynamic detuning) to stabilize beam intensity or position. Obviously, any change in angular alignment of the monochromator crystals will also induce deviations in the beam trajectory and photon energy distribution. At the microXAS undulator beamline of the SLS, we have implemented a system to achieve a constant I0. Two wedge-shaped absorbers produce a spatially uniform attenuation preserving the beam shape without introducing changes in its trajectory. Hardware, control loop and system performance will be presented.
[1] F.Bridges, Nuclear Instruments and Methods in Physics Research A257 (1987) 447-450.
[2] H.Kitamura, J.Synchrotron Rad. 7 (2000), 121-130.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-THPH04

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPH15

A New High Precision, Fully Motorized 6-DoF Sample Stage for the ALBA PEEM Endstation

GUI, controls, resonance, vacuum

368

N. Gonzalez, L. Aballe, A. Carballedo, C. Colldelram, M. Foerster
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

A new 6-DOF sample manipulator has been designed for the ALBA Synchrotron PhotoEmission Electron Microscopy (PEEM) experimental station, based on a commercial Elmitec LEEM 3. The new design includes full motorization of all 6 axes with position feedback, no backlash, and maximized stability, crucial to achieve the best spatial resolution of down to 8 nm (in so-called LEEM mode). The in-plane longitudinal and transversal motions with sub-micron resolution are based on high precision linear guides, while the pitch and roll stages (sample tilt), guided by angular guides, are actuated by a double-flexure system, which enhances the overall rigidity of the system. The vertical stage is composed by a high rigidity recirculating roller screw and cross roller guides. Finally, 360° yaw rotation is supplied by a differentially pumped commercial rotary stage. On top of the stage, the sample support is mounted on a customized DN63CF flange. This support keeps the original functionalities of the sample manipulator and holders, with 6 independent electrical contacts, and the possibility to heat the sample up to 2000 K and cool it to 100 K with an improved liquid nitrogen cooling system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-THPH15

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPH16

Compact Mirror Bender With Sub-Nanometer Adaptive Correction Control

optics, controls, synchrotron, focusing

371

N. Gonzalez, C. Colldelram, J.B. González Fernández, J. Juanhuix, J. Nicolás, C. Ruget
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

Funding: This work is partially funded by MINECO under contract FIS2015-66328-C3-2-R and by ERDF funds.
We present a compact mirror bender with dynamic surface correction. The system is the evolution of an in-house development and will be the default focusing system for the new ALBA beamlines. The bender is now more compact and can introduce stronger curvatures, as required for microfocus applications. It allows for in-situ correction of the mirror surface, with resolution and stability below one nanometer. The bender can compensate parasitic deformations caused by thermal bumps, changes of focus, or stresses appeared during installation or bakeout. The system includes two torque actuators at the ends of the mirror as well as a number of correctors along the mirror length, capable of introducing high order surface corrections. The bending curvature is actively stabilized, by a feedback loop that controls the applied force, to the equivalent of 0.25 nm rms in a 500 mm long mirror. The figure correctors provide up to 20N push-pull force with resolution below .001 N. They combine elastic and magnetic forces to improve their stability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2018-THPH16

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)