MEDSI2016 - Classification: Precision Mechanics / Stability

Paper	Title	Page
MOPE01	Stabilization Methods for Force Actuators and Flexure Hinges	1
	C. Colldelram, J. Nicolás, C. Ruget ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	In the framework of the design of an adaptive optics for x-ray mirrors a stabilization system* for force actuators and flexure hinges have been conceived. This corrector allows to deform the mirror surface at nanometre level but for this purpose it requires resolutions better than 0.02, by using ultra-low constant springs, and to preserve the introduced deformation it is needed to be stable at the same level. The corrector needs to be insensitive when dismantling and remounting the mirror. In the other hand in order to support the corrector its structure is attached to the bender frame and the spring force is transmitted through a level arm by means a bearing articulation. This introduces a small friction but it is still preferably to eliminate it. A new method based -k spring-like constant principle is proposed. Based on this technique it is possible to stabilize the force exerted on the mirror below 0,02N for an error range more than 1 mm. In addition applying the principle to a flexure it allows to compensate it in an angular range in within the torque variation tend to be null, below 0,005 Nm, thus becoming a short range, frictionless and zero torque articulation. * Patent Registered
	Poster MOPE01 [1.046 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE01
About •	paper received ※ 15 September 2016 paper accepted ※ 08 May 2017 issue date ※ 22 June 2017
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MOPE02	Studies on Flow-Induced Vibrations for the New High-Dynamics DCM for Sirius	8
	R.M. Caliari, O.R. Bagnato, F.R. Francisco, R.R. Geraldes, R.L. Parise, M. Saveri Silva, D.O. Tavares, L.,Jr. de Souza LNLS, Campinas, Brazil T.A.M. Ruijl MI-Partners, Eindhoven, The Netherlands
	The monochromator is known to be one of the most critical optical elements of a synchrotron beamline, since it directly affects the beam quality with respect to energy and position. Naturally, the new 4th generation machines, with their small emittances, start to bring about higher stability performance requirements, in spite of factors as high power loads, power load variation, and vibration sources. A new high-dynamics DCM (Double Crystal Monochromator) is under development at the Brazilian Light Source for the Sirius EMA beamline (Extreme Condition X-ray Methods of Analysis). The disturbances induced by the coolant flows are known to be among the most detrimental influences to a DCM performance, however, quantitative force numbers involved in such disturbances are not commonly investigated. According to the novel dynamic concept, these forces should be predictably translated into stability performance. Therefore, experimental setups that allow the indirect measurement of such forces in conditions close to those of operation were designed. The results comparing different indirect cooling profiles and manufacturing processes (brazing and additive manufacturing) are shown.
	Poster MOPE02 [3.064 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE02
About •	paper received ※ 09 September 2016 paper accepted ※ 15 September 2016 issue date ※ 22 June 2017
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MOPE04	Dynamically Isotropic Hexapods for High-Performance 6-DOF Manipulation
	B. Afzali-Far MAX IV Laboratory, Lund University, Lund, Sweden
	Recent advances in synchrotron facilities have led to a growing need for 6-DOF precise manipulation. Hexapods are the most widely used parallel robots which provide 6 DOFs. To obtain high precision and high dynamic performance in hexapods, it is necessary to design them in such a way that low eigen frequencies are avoided (while the eigenf requencies are also functions of the complex 3D geometry of hexapods). Theoretically, maximizing the lowest eigen frequency leads to a condition where multiple eigen frequencies become equal, which is known as (complete or partial) dynamic isotropy. Thus, one may consider a dynamically isotropic hexapod as the optimal design solution, where precision and dynamic performance is a goal. In this work, we analytically address this problem and establish a practical guideline in order to design generalized hexapods with complete dynamic isotropy. The findings are based on the recently defended PhD dissertation by Behrouz Afzali-Far.
	Poster MOPE04 [0.853 MB]
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MOPE05	Mechanical Design of Secondary Source Slits for Hard X-ray Beamlines at Taiwan Photon Source	12
	H.Y. Yan, C.H. Chang, S.H. Chang, C.Y. Chen, C.Y. Huang, J.M. Lin, D.G. Liu, D.-J. Wang NSRRC, Hsinchu, Taiwan
	The secondary source slits have been developed for specific hard X-ray beam-lines at Taiwan Photon Source. Especially for Coherent X-ray Scattering and X-ray Nanoprobe beam-lines, severe specifications of the slits are more necessary to define proper beam sizes in horizontal and vertical directions at sample. The opening size of each pair of slits assembled orthogonally is usually needed to range within several microns, so the UHV-compatible piezo-driven stages with closed-loop system were adopted for the purposes of fine adjustment, precise positional accuracy and repeatability. To reduce X-ray scattering effect, the rectangular single-crystal film was bonded on the edge of the slit blade. The machined rotary weak-link structure and piezo-driven actuators were used to slightly adjust parallelism of each pair of the blades with the method of single-slit diffraction. To enhance structural and thermal stability, the granite plinths with specified shape were designed and the precise temperature controlling system will be set up recently. The overall design, mechanical specifications and procedure of testing for secondary source slits will be introduced in this paper.
	Poster MOPE05 [0.795 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE05
About •	paper received ※ 09 September 2016 paper accepted ※ 14 September 2016 issue date ※ 22 June 2017
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MOPE06	The Mechanical Stability and the Correlated Beam Performance at TPS
	J.-R. Chen, M.L. Chen, W.Y. Lai, Z.-D. Tsai, Y.C. Yang NSRRC, Hsinchu, Taiwan
	The correlation between the mechanical stability and the beam performance at TPS was studied. Strong correlation was observed between the air temperature fluctuation and the fluctuations of the beam size and beam position. It was found that different temperature sources were responsible for the fluctuations of the beam position in different directions (vertical and horizontal). The sensitivity factors of the fluctuations of the beam performance to the temperature fluctuation were measured.
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MOPE07	Ground Motions Measurements for Synchrotron	15
	D.T. Ziemianski CUT, Kraków, Poland M.P. Nowak Solaris, Kraków, Poland
	For more than two decades, ground vibration measurements were made by different teams for feasibility studies of linear accelerators. Recent measurements were performed in the SPS tunnel and at different CERN sites on the surface. The devices to measure vibrations of magnitude ranging in nanometres, the analysis techniques and the results are critically discussed and compared with the former measurements. The implication of the measured integrated R.M.S. displacements for the Crab cavities cavern is mentioned. The equipment used in this study consists of 2 state-of-the-art Guralp broadband triaxial seismometers. Models CMG-T60-0004 performed measurements in three directions V, N/S and E/W. The first analysis was to evaluate the power spectral density for each direction of sensors and event. The power spectral density is calculated from the auto power spectrum. The power spectral density shows a typical curve for the geophones with theμseismic peak between 0.2 and 0.4 [Hz]. It is import ant to point that ground vibrations should not be ignored in planning accelerator facility. Actually it is one of the limiting factor in the optimization of future accelerators.
	Poster MOPE07 [4.968 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE07
About •	paper received ※ 09 September 2016 paper accepted ※ 15 September 2016 issue date ※ 22 June 2017
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MOPE08	The LNLS Metrology Building	17
	H.G.P. de Oliveira, C. Esper Neto, P.T. Fonseca, R.R. Geraldes, B.C. Meyer, M.A. Pereira, G.L.M.P. Rodrigues, L. Sanfelici, L.G. da Silva LNLS, Campinas, Brazil L. Buccianti, M.H.A. Costa Biotec Controle Ambiental, São José dos Campos, SP, Brazil C. Prudente Prudente Engenharia Ltda., Uberlândia, Minas Gerais, Brazil
	Funding: Brazilian Ministry of Science, Technology, Innovation and Communication. The increasing demands of instrumentation projects for SIRIUS require more sensitive equipment to be devel-oped and characterized in theμand nanometer scale. To achieve this level of precision it is necessary to work within a controlled environment, minimizing instabilities and disturbance effects such as temperature variation and vibrations. Based on metrology labs as those at BESSY, ESRF, DLS and others, a new facility is currently under final construction stage at the LNLS, which will be dedi-cated to high precision optical and mechanical metrolo-gies. This work describes in detail the project of the new LNLS Metrology Building.
	Poster MOPE08 [2.829 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE08
About •	paper received ※ 09 September 2016 paper accepted ※ 15 September 2016 issue date ※ 22 June 2017
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MOPE09	Preliminary Design and Test of Damping Mechanism for Reducing Vibration of TPS SR Vacuum Chamber	20
	K.H. Hsu, M.L. Chen, C.M. Cheng, H.C. Ho, D.-G. Huang, C.K. Kuan, W.Y. Lai, C.J. Lin, S.Y. Perng, T.C. Tseng, H.S. Wang NSRRC, Hsinchu, Taiwan
	Since flow-induced vibration of vacuum chamber effects of the stability of the electron beam storage ring in Taiwan Photon Source (TPS), a damping mechanism was designed and installed to reduce vibration. The damping mechanism is composed of a clamper of vacuum chamber, a fixed fixture on the girder and a sandwiched stain-less steel support with damping materials inside. Different kinds of materials were applied in the damping mechanism for vacuum chamber. The vibration of vacuum chamber were obtained and compared. The design and vibration measurement results of damping mechanism for vacuum chamber are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE09
About •	paper received ※ 11 September 2016 paper accepted ※ 14 September 2016 issue date ※ 22 June 2017
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MOPE10	Dynamic Analysis and Measurement of Ground Motion for the Solaris - National Synchrotron Radiation Centre in Cracow	24
	D.T. Ziemianski CUT, Kraków, Poland M.P. Nowak Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
	The paper presents the results of the ground motion measurements and dynamic analysis performed in the Polish synchrotron radiation facility Solaris. The analysis has been carried out within the framework of the installation experimental lines inside Solaris building and accelerator tunnel. The equipment used in this study consists of 4 seismic, high sensitivity, ceramic flexural ICP accelerometer Models 393B31 (PCB), which performed measurements in one vertical directions. The first analysis was to evaluate the power spectral density for each sensors and event. The power spectral density is calculated from the auto power spectrum. The power spectral density shows a typical curve with theμseismic peak between 0.2 and 0.4 Hz. It is important to point that ground vibrations should not be ignored in planning accelerator facility. All over the measurement, the RMS integrated level in the vertical direction at 1 Hz were calculated and presented in paper.
	Poster MOPE10 [2.916 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE10
About •	paper received ※ 09 September 2016 paper accepted ※ 23 September 2016 issue date ※ 22 June 2017
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MOPE11	Preliminary Active Vibration Elimination Study of the TPS Girder System	26
	T.C. Tseng, M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, W.Y. Lai, C.J. Lin, S.Y. Perng, C.W. Tsai, H.S. Wang NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) had delivered the first synchrotron light on the last day of 2014 and is to open to the users from September 2016 after one and half years of commissioning and insertion devices installation. However, the instability is still an obvious problem to the beam quality and the deviation amplification factor of the magnets to the electron beam plays an important contribution role. Since the magnets are firmly installed on the girders and the contribution is mainly transferred from the girder vibration. This study tries to eliminate the obvious vibration frequencies amplitude exerted on the girder from outside sources such as the utility system with the PZT actuators installed on the locking wedges between girder and pedestals. By the amplitude and inverse phase searching iteration, some vibration frequency peaks in phase domain can be eliminated and the instability is also reduced.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE11
About •	paper received ※ 11 September 2016 paper accepted ※ 20 September 2016 issue date ※ 22 June 2017
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TUCA01	Investigation of the Vibrational Stability of Synchrotron X-Ray Optics Using a Differential Interferometer
	R. Doehrmann, J. Heuer, J. Horbach, H. Schulte Schrepping, I. Sergeev DESY, Hamburg, Germany
	Advanced synchrotron radiation experiments for example for investigations at the nanoscale place extreme demands on the stability and precision of all components of modern beamlines. This is of particular importance for high precision X-ray optics, as mirrors or double crystal monochromators (DCM), which should keep the beam stable. The DCM is the first optical element in most synchrotron beamlines, which has to operate under high heat load. Thus, the cryogenic cooling and high vacuum are necessary conditions for the DCM operation in most cases. Unfortunately, cryogenic cooling is a source of the vibrational instability that has to be reduced in order to improve the beamline performance. Here, we present a method to measure vibration directly at the DCM crystals. This method was used to study and improve vibrational stability of several PETRA III monochromators. The results of the measurements allow us to discover common sources of instabilities. These results will be shown and discussed and we will describe in detail the modifications performed on the LN2 system and the monochromator design, which leads to the improvement of the angular stability at the best down to 50 nrad RMS.
	Slides TUCA01 [9.083 MB]
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TUCA02	Structural Dynamic Modelling and Measurement of SwissFEL Bunch Compressor	128
	X. Wang, H. Jöhri, F. Löhl, M. Pedrozzi, T. Stapf PSI, Villigen PSI, Switzerland
	Magnetic chicanes are used in accelerator facilities to longitudinally compress the accelerated particle bunches. The second compression chicane (BC2) of SwissFEL consists of four dipole magnets bending the beam on the horizontal plane along a C-shaped orbit and has a total length of 17 m. The position of the two central dipoles can be continuously adjusted to achieve the required transverse offset in order to realize a wide range of compression schemes. To ensure the requires mechanical stability of the accelerator components sitting on the long and movable steel girder (7.7 m), it is essential to design a stiff support structure with high eigen frequencies. In the design stage, displacement frequency responses are calculated in a modal based linear dynamic analysis using finite element method to ensure vibration amplitude below 1 micrometer. Special considerations are given to the modelling of linear guide systems, as they introduce nonlinear support conditions and need to be adequately simplified in the calculation. After completing the BC2 assembly, vibration measurements were performed. Finally, the validation of the numerical model by measurement results will be presented.
	Slides TUCA02 [3.884 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUCA02
About •	paper received ※ 10 September 2016 paper accepted ※ 20 September 2016 issue date ※ 22 June 2017
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TUCA03	Estimation of the Temperature Fluctuations Harshness Regarding Stability of Structures in the Nanometer Range	133
	N. Jobert, F. Alves, S.K. Kubsky SOLEIL, Gif-sur-Yvette, France
	Thermally induced distortions are a key contributor to the overall positional and pointing performance of high-stability systems. Though stability scales with temperature fluctuations, there is some hidden complexity is the subject. Firstly, not all temperature oscillations will distort the structure: fast variations will hardly propagate into the structure, little change in overall dimensions but primarily pointing errors. Conversely, slow variations will result in quasi uniform temperature fields that change dimensions, hence mainly positional errors. Secondly, there is randomness in temperature fluctuations which obscures the actual severity of a given environment: randomness occurs timewise, but also space-wise. For highly stable situations, random part of the temperature field becomes prominent, and discarding this component becomes questionable. No harshness indicator exists that could help quantifying the actual severity of a given thermal environment. It is the objective of this paper to provide some insight on the matter, and propose a simple yet efficient numerical method allowing the evaluation of actual structural response to any realistic thermal environment.
	Slides TUCA03 [7.080 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUCA03
About •	paper received ※ 01 September 2016 paper accepted ※ 20 September 2016 issue date ※ 22 June 2017
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TUCA04	Vibrational Stability of a Cryocooled Horizontal-Bounce Double Crystal Monochromator
	P. Kristiansen FMB Oxford, Oxford, United Kingdom
	There is an increasing demand on monochromators to preserve the performance of the latest ultra-stable storage rings. One method of obtaining near-complete vertical preservation of the ring stability is to arrange the crystals in a horizontal diffracting geometry. We present the vibrational performance of a fixed offset Horizontal Double Crystal Monochromator. We have made direct measurements, at cryocooled conditions, on a H-DCM currently deployed at MAX IV that has a relative pitch stability of 25 nrad RMS, 1-2500 Hz, and an absolute pitch stability of 18 nrad RMS, 2-2500 Hz, when running the cryocooler in a condition that allows 1.5kW to be extracted via the circulating liquid nitrogen. These results demonstrate the advantage in terms of vibrational stability of circulating the liquid nitrogen high pressures, which enables the flow velocities to be reduced to obtain equivalent cooling performance. The value of performing live measurements is illustrated as we show that a vibration of the in-vacuum cryoline support structure is not translated into relative crystal vibrations, contrary to the intuitive assumption that this would be the primary source of beam instability.
	Slides TUCA04 [2.423 MB]
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Paper

Title

Page

Stabilization Methods for Force Actuators and Flexure Hinges

1

C. Colldelram, J. Nicolás, C. Ruget
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

In the framework of the design of an adaptive optics for x-ray mirrors a stabilization system* for force actuators and flexure hinges have been conceived. This corrector allows to deform the mirror surface at nanometre level but for this purpose it requires resolutions better than 0.02, by using ultra-low constant springs, and to preserve the introduced deformation it is needed to be stable at the same level. The corrector needs to be insensitive when dismantling and remounting the mirror. In the other hand in order to support the corrector its structure is attached to the bender frame and the spring force is transmitted through a level arm by means a bearing articulation. This introduces a small friction but it is still preferably to eliminate it. A new method based -k spring-like constant principle is proposed. Based on this technique it is possible to stabilize the force exerted on the mirror below 0,02N for an error range more than 1 mm. In addition applying the principle to a flexure it allows to compensate it in an angular range in within the torque variation tend to be null, below 0,005 Nm, thus becoming a short range, frictionless and zero torque articulation.
* Patent Registered

Poster MOPE01 [1.046 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE01

About •

paper received ※ 15 September 2016 paper accepted ※ 08 May 2017 issue date ※ 22 June 2017

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MOPE02

Studies on Flow-Induced Vibrations for the New High-Dynamics DCM for Sirius

8

R.M. Caliari, O.R. Bagnato, F.R. Francisco, R.R. Geraldes, R.L. Parise, M. Saveri Silva, D.O. Tavares, L.,Jr. de Souza
LNLS, Campinas, Brazil
T.A.M. Ruijl
MI-Partners, Eindhoven, The Netherlands

The monochromator is known to be one of the most critical optical elements of a synchrotron beamline, since it directly affects the beam quality with respect to energy and position. Naturally, the new 4th generation machines, with their small emittances, start to bring about higher stability performance requirements, in spite of factors as high power loads, power load variation, and vibration sources. A new high-dynamics DCM (Double Crystal Monochromator) is under development at the Brazilian Light Source for the Sirius EMA beamline (Extreme Condition X-ray Methods of Analysis). The disturbances induced by the coolant flows are known to be among the most detrimental influences to a DCM performance, however, quantitative force numbers involved in such disturbances are not commonly investigated. According to the novel dynamic concept, these forces should be predictably translated into stability performance. Therefore, experimental setups that allow the indirect measurement of such forces in conditions close to those of operation were designed. The results comparing different indirect cooling profiles and manufacturing processes (brazing and additive manufacturing) are shown.

Poster MOPE02 [3.064 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE02

About •

paper received ※ 09 September 2016 paper accepted ※ 15 September 2016 issue date ※ 22 June 2017

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MOPE04

Dynamically Isotropic Hexapods for High-Performance 6-DOF Manipulation

B. Afzali-Far
MAX IV Laboratory, Lund University, Lund, Sweden

Recent advances in synchrotron facilities have led to a growing need for 6-DOF precise manipulation. Hexapods are the most widely used parallel robots which provide 6 DOFs. To obtain high precision and high dynamic performance in hexapods, it is necessary to design them in such a way that low eigen frequencies are avoided (while the eigenf requencies are also functions of the complex 3D geometry of hexapods). Theoretically, maximizing the lowest eigen frequency leads to a condition where multiple eigen frequencies become equal, which is known as (complete or partial) dynamic isotropy. Thus, one may consider a dynamically isotropic hexapod as the optimal design solution, where precision and dynamic performance is a goal. In this work, we analytically address this problem and establish a practical guideline in order to design generalized hexapods with complete dynamic isotropy. The findings are based on the recently defended PhD dissertation by Behrouz Afzali-Far.

Poster MOPE04 [0.853 MB]

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MOPE05

Mechanical Design of Secondary Source Slits for Hard X-ray Beamlines at Taiwan Photon Source

12

H.Y. Yan, C.H. Chang, S.H. Chang, C.Y. Chen, C.Y. Huang, J.M. Lin, D.G. Liu, D.-J. Wang
NSRRC, Hsinchu, Taiwan

The secondary source slits have been developed for specific hard X-ray beam-lines at Taiwan Photon Source. Especially for Coherent X-ray Scattering and X-ray Nanoprobe beam-lines, severe specifications of the slits are more necessary to define proper beam sizes in horizontal and vertical directions at sample. The opening size of each pair of slits assembled orthogonally is usually needed to range within several microns, so the UHV-compatible piezo-driven stages with closed-loop system were adopted for the purposes of fine adjustment, precise positional accuracy and repeatability. To reduce X-ray scattering effect, the rectangular single-crystal film was bonded on the edge of the slit blade. The machined rotary weak-link structure and piezo-driven actuators were used to slightly adjust parallelism of each pair of the blades with the method of single-slit diffraction. To enhance structural and thermal stability, the granite plinths with specified shape were designed and the precise temperature controlling system will be set up recently. The overall design, mechanical specifications and procedure of testing for secondary source slits will be introduced in this paper.

Poster MOPE05 [0.795 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE05

About •

paper received ※ 09 September 2016 paper accepted ※ 14 September 2016 issue date ※ 22 June 2017

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MOPE06

The Mechanical Stability and the Correlated Beam Performance at TPS

J.-R. Chen, M.L. Chen, W.Y. Lai, Z.-D. Tsai, Y.C. Yang
NSRRC, Hsinchu, Taiwan

The correlation between the mechanical stability and the beam performance at TPS was studied. Strong correlation was observed between the air temperature fluctuation and the fluctuations of the beam size and beam position. It was found that different temperature sources were responsible for the fluctuations of the beam position in different directions (vertical and horizontal). The sensitivity factors of the fluctuations of the beam performance to the temperature fluctuation were measured.

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MOPE07

Ground Motions Measurements for Synchrotron

15

D.T. Ziemianski
CUT, Kraków, Poland
M.P. Nowak
Solaris, Kraków, Poland

For more than two decades, ground vibration measurements were made by different teams for feasibility studies of linear accelerators. Recent measurements were performed in the SPS tunnel and at different CERN sites on the surface. The devices to measure vibrations of magnitude ranging in nanometres, the analysis techniques and the results are critically discussed and compared with the former measurements. The implication of the measured integrated R.M.S. displacements for the Crab cavities cavern is mentioned. The equipment used in this study consists of 2 state-of-the-art Guralp broadband triaxial seismometers. Models CMG-T60-0004 performed measurements in three directions V, N/S and E/W. The first analysis was to evaluate the power spectral density for each direction of sensors and event. The power spectral density is calculated from the auto power spectrum. The power spectral density shows a typical curve for the geophones with theμseismic peak between 0.2 and 0.4 [Hz]. It is import ant to point that ground vibrations should not be ignored in planning accelerator facility. Actually it is one of the limiting factor in the optimization of future accelerators.

Poster MOPE07 [4.968 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE07

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paper received ※ 09 September 2016 paper accepted ※ 15 September 2016 issue date ※ 22 June 2017

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MOPE08

The LNLS Metrology Building

17

H.G.P. de Oliveira, C. Esper Neto, P.T. Fonseca, R.R. Geraldes, B.C. Meyer, M.A. Pereira, G.L.M.P. Rodrigues, L. Sanfelici, L.G. da Silva
LNLS, Campinas, Brazil
L. Buccianti, M.H.A. Costa
Biotec Controle Ambiental, São José dos Campos, SP, Brazil
C. Prudente
Prudente Engenharia Ltda., Uberlândia, Minas Gerais, Brazil

Funding: Brazilian Ministry of Science, Technology, Innovation and Communication.
The increasing demands of instrumentation projects for SIRIUS require more sensitive equipment to be devel-oped and characterized in theμand nanometer scale. To achieve this level of precision it is necessary to work within a controlled environment, minimizing instabilities and disturbance effects such as temperature variation and vibrations. Based on metrology labs as those at BESSY, ESRF, DLS and others, a new facility is currently under final construction stage at the LNLS, which will be dedi-cated to high precision optical and mechanical metrolo-gies. This work describes in detail the project of the new LNLS Metrology Building.

Poster MOPE08 [2.829 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE08

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paper received ※ 09 September 2016 paper accepted ※ 15 September 2016 issue date ※ 22 June 2017

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MOPE09

Preliminary Design and Test of Damping Mechanism for Reducing Vibration of TPS SR Vacuum Chamber

20

K.H. Hsu, M.L. Chen, C.M. Cheng, H.C. Ho, D.-G. Huang, C.K. Kuan, W.Y. Lai, C.J. Lin, S.Y. Perng, T.C. Tseng, H.S. Wang
NSRRC, Hsinchu, Taiwan

Since flow-induced vibration of vacuum chamber effects of the stability of the electron beam storage ring in Taiwan Photon Source (TPS), a damping mechanism was designed and installed to reduce vibration. The damping mechanism is composed of a clamper of vacuum chamber, a fixed fixture on the girder and a sandwiched stain-less steel support with damping materials inside. Different kinds of materials were applied in the damping mechanism for vacuum chamber. The vibration of vacuum chamber were obtained and compared. The design and vibration measurement results of damping mechanism for vacuum chamber are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE09

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paper received ※ 11 September 2016 paper accepted ※ 14 September 2016 issue date ※ 22 June 2017

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MOPE10

Dynamic Analysis and Measurement of Ground Motion for the Solaris - National Synchrotron Radiation Centre in Cracow

24

D.T. Ziemianski
CUT, Kraków, Poland
M.P. Nowak
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland

The paper presents the results of the ground motion measurements and dynamic analysis performed in the Polish synchrotron radiation facility Solaris. The analysis has been carried out within the framework of the installation experimental lines inside Solaris building and accelerator tunnel. The equipment used in this study consists of 4 seismic, high sensitivity, ceramic flexural ICP accelerometer Models 393B31 (PCB), which performed measurements in one vertical directions. The first analysis was to evaluate the power spectral density for each sensors and event. The power spectral density is calculated from the auto power spectrum. The power spectral density shows a typical curve with theμseismic peak between 0.2 and 0.4 Hz. It is important to point that ground vibrations should not be ignored in planning accelerator facility. All over the measurement, the RMS integrated level in the vertical direction at 1 Hz were calculated and presented in paper.

Poster MOPE10 [2.916 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE10

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paper received ※ 09 September 2016 paper accepted ※ 23 September 2016 issue date ※ 22 June 2017

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MOPE11

Preliminary Active Vibration Elimination Study of the TPS Girder System

26

T.C. Tseng, M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, W.Y. Lai, C.J. Lin, S.Y. Perng, C.W. Tsai, H.S. Wang
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) had delivered the first synchrotron light on the last day of 2014 and is to open to the users from September 2016 after one and half years of commissioning and insertion devices installation. However, the instability is still an obvious problem to the beam quality and the deviation amplification factor of the magnets to the electron beam plays an important contribution role. Since the magnets are firmly installed on the girders and the contribution is mainly transferred from the girder vibration. This study tries to eliminate the obvious vibration frequencies amplitude exerted on the girder from outside sources such as the utility system with the PZT actuators installed on the locking wedges between girder and pedestals. By the amplitude and inverse phase searching iteration, some vibration frequency peaks in phase domain can be eliminated and the instability is also reduced.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-MOPE11

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paper received ※ 11 September 2016 paper accepted ※ 20 September 2016 issue date ※ 22 June 2017

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TUCA01

Investigation of the Vibrational Stability of Synchrotron X-Ray Optics Using a Differential Interferometer

R. Doehrmann, J. Heuer, J. Horbach, H. Schulte Schrepping, I. Sergeev
DESY, Hamburg, Germany

Advanced synchrotron radiation experiments for example for investigations at the nanoscale place extreme demands on the stability and precision of all components of modern beamlines. This is of particular importance for high precision X-ray optics, as mirrors or double crystal monochromators (DCM), which should keep the beam stable. The DCM is the first optical element in most synchrotron beamlines, which has to operate under high heat load. Thus, the cryogenic cooling and high vacuum are necessary conditions for the DCM operation in most cases. Unfortunately, cryogenic cooling is a source of the vibrational instability that has to be reduced in order to improve the beamline performance. Here, we present a method to measure vibration directly at the DCM crystals. This method was used to study and improve vibrational stability of several PETRA III monochromators. The results of the measurements allow us to discover common sources of instabilities. These results will be shown and discussed and we will describe in detail the modifications performed on the LN2 system and the monochromator design, which leads to the improvement of the angular stability at the best down to 50 nrad RMS.

Slides TUCA01 [9.083 MB]

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TUCA02

Structural Dynamic Modelling and Measurement of SwissFEL Bunch Compressor

128

X. Wang, H. Jöhri, F. Löhl, M. Pedrozzi, T. Stapf
PSI, Villigen PSI, Switzerland

Magnetic chicanes are used in accelerator facilities to longitudinally compress the accelerated particle bunches. The second compression chicane (BC2) of SwissFEL consists of four dipole magnets bending the beam on the horizontal plane along a C-shaped orbit and has a total length of 17 m. The position of the two central dipoles can be continuously adjusted to achieve the required transverse offset in order to realize a wide range of compression schemes. To ensure the requires mechanical stability of the accelerator components sitting on the long and movable steel girder (7.7 m), it is essential to design a stiff support structure with high eigen frequencies. In the design stage, displacement frequency responses are calculated in a modal based linear dynamic analysis using finite element method to ensure vibration amplitude below 1 micrometer. Special considerations are given to the modelling of linear guide systems, as they introduce nonlinear support conditions and need to be adequately simplified in the calculation. After completing the BC2 assembly, vibration measurements were performed. Finally, the validation of the numerical model by measurement results will be presented.

Slides TUCA02 [3.884 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUCA02

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paper received ※ 10 September 2016 paper accepted ※ 20 September 2016 issue date ※ 22 June 2017

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TUCA03

Estimation of the Temperature Fluctuations Harshness Regarding Stability of Structures in the Nanometer Range

133

N. Jobert, F. Alves, S.K. Kubsky
SOLEIL, Gif-sur-Yvette, France

Thermally induced distortions are a key contributor to the overall positional and pointing performance of high-stability systems. Though stability scales with temperature fluctuations, there is some hidden complexity is the subject. Firstly, not all temperature oscillations will distort the structure: fast variations will hardly propagate into the structure, little change in overall dimensions but primarily pointing errors. Conversely, slow variations will result in quasi uniform temperature fields that change dimensions, hence mainly positional errors. Secondly, there is randomness in temperature fluctuations which obscures the actual severity of a given environment: randomness occurs timewise, but also space-wise. For highly stable situations, random part of the temperature field becomes prominent, and discarding this component becomes questionable. No harshness indicator exists that could help quantifying the actual severity of a given thermal environment. It is the objective of this paper to provide some insight on the matter, and propose a simple yet efficient numerical method allowing the evaluation of actual structural response to any realistic thermal environment.

Slides TUCA03 [7.080 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUCA03

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paper received ※ 01 September 2016 paper accepted ※ 20 September 2016 issue date ※ 22 June 2017

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TUCA04

Vibrational Stability of a Cryocooled Horizontal-Bounce Double Crystal Monochromator

P. Kristiansen
FMB Oxford, Oxford, United Kingdom

There is an increasing demand on monochromators to preserve the performance of the latest ultra-stable storage rings. One method of obtaining near-complete vertical preservation of the ring stability is to arrange the crystals in a horizontal diffracting geometry. We present the vibrational performance of a fixed offset Horizontal Double Crystal Monochromator. We have made direct measurements, at cryocooled conditions, on a H-DCM currently deployed at MAX IV that has a relative pitch stability of 25 nrad RMS, 1-2500 Hz, and an absolute pitch stability of 18 nrad RMS, 2-2500 Hz, when running the cryocooler in a condition that allows 1.5kW to be extracted via the circulating liquid nitrogen. These results demonstrate the advantage in terms of vibrational stability of circulating the liquid nitrogen high pressures, which enables the flow velocities to be reduced to obtain equivalent cooling performance. The value of performing live measurements is illustrated as we show that a vibration of the in-vacuum cryoline support structure is not translated into relative crystal vibrations, contrary to the intuitive assumption that this would be the primary source of beam instability.

Slides TUCA04 [2.423 MB]

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