A new IR beamline has been scheduled at TPS beam-line construction Phase III. The new beamline optical design is following the structure of the existed TLS IR beamline. However, the focusing mirrors has to be re-deign according to different situation. These KB type mirrors (HFM and VFM) are same thickness flat stain-less plates assembled with bending arms and bended with single motor each to fit quintic polynomial surface pro-files for focusing and also modifying arc source effect of bending section. For a same thickness plate in addition with the bending arms effect to form a desired polynomi-al surface profile, it demands specific width distribution. With the drawing method and FEM iteration simulation, the optimized surface polynomial equation and width distribution design of the mirror plates were defined. The detailed design sequences will be described in this paper.
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Funding:This research benefited from a FRIA grant from the French Community of Belgium. With the growing number of fourth generation light sources, there is an increased need of fast positioning end-stations with nanometric precision. Such systems are usually including dedicated control strategies, and many factors may limit their performances. In order to design such complex systems in a predictive way, a mechatronic design approach also known as "model based design", may be utilized. In this paper, we present how this mechatronic design approach was used for the development of a nano-hexapod for the ESRF ID31 beamline. The chosen design approach consists of using models of the mechatronic system (including sensors, actuators and control strategies) to predict its behavior. Based on this behavior and closed-loop simulations, the elements that are limiting the performances can be identified and re-designed accordingly. This allows to make adequate choices concerning the design of the nano-hexapod and the overall mechatronic architecture early in the project and save precious time and resources. Several test benches were used to validate the models and to gain confidence on the predictability of the final system’s performances. Measured nano-hexapod’s dynamics was shown to be in very good agreement with the models. Further tests should be done in order to confirm that the performances of the system match the predicted one. The presented development approach is foreseen to be applied more frequently to future mechatronic system design at the ESRF.
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Z. Qiao, J.W.J. Anton, L. Assoufid, S.P. Kearney, S.T. Mashrafi, J. Qian, X. Shi, D. Shu
ANL, Lemont, Illinois, USA
Funding:Work supported by the U.S. Department of Energy, Office of Science under Control DE-AC02-06CH11357 Deformable optics, including mechanically-bent and bimorph mirrors, are essential optical elements for X-ray beam dynamical focusing and wavefront correction. Existing mechanical bender technology often suffers from poor repeatability and does not include twist compensation. We recently developed an elliptically bent mirror based on a laminar flexure bending mechanism that yielded promising results*,**. In this work, the mirror surface twist was characterized using a Fizeau interferometer under different bending conditions. By applying a shimming correction, the surface twist was successfully reduced from 50 urad to 1.5 urad. The twist angle variation from no bending to the maximum bending is less than 0.5 urad. Our simulation results show that these numbers are significantly lower than the required values to ensure optimum optical performance. The study demonstrates the effectiveness of the twist compensation procedures and validates the mirror bender design parameters. *Shu, D. et al., AIP Conference Proceedings. Vol. 2054. No. 1, 2019. **Anton, Jayson WJ et al., Optomechanical Engineering 2019. Vol. 11100, 2019.
O. Utke
Synchrotron Light Research Institute (SLRI), Muang District, Thailand
S. Chaichuay, S. Klinkhieo, S. Pongampai, K. Sittisard, S. Srichan
SLRI, Nakhon Ratchasima, Thailand
The new Siam Photon Source II (SPS-II) storage ring is designed with a circumference of 327.502 m. It consists of 14 DTBA cell, where each cell requires 6 magnet girders. For the new storage ring of SPS II we developed a magnet girder system which uses wedgemounts for the precision alignment. The girder alignment uses a 3-2-1 alignment method and requires 3 wedgemounts to control Z direction, 2 wedgemounts to control Y-direction and 1 wedgemount for the X-direction. The magnet alignment is based on mechanical tolerances. Therefore, the girders top plate is prepared with precision surfaces with a flatness tolerance of 30 µm. During the development process of the girder system deformation and vibration FEA analysis were carried out and the results were used to improve the design regarding low deformation and high natural frequencies. In this paper FEA analysis results are presented as well as the design of the girder, pedestal and its wedgemount based alignment system.
X.J. Nie, L. Kang, R.H. Liu, S.K. Tian
IHEP, Beijing, People’s Republic of China
J.X. Chen, H.Y. He, L. Liu, C.J. Ning, A.X. Wang, G.Y. Wang, J.B. Yu, Y.J. Yu, J.S. Zhang, D.H. Zhu
IHEP CSNS, Guangdong Province, People’s Republic of China
The design of shield structure for bellow is an im-portant content for the research of beam position monitor (BPM). The bellow shield structure consists of contact fingers and spring fingers. Several alternative schemes for bellow shield were achieved based on BPM detailed structure. The optimal scheme was achieved by the im-pedance simulation analysis with CST. The dimension of the contact finger was decided based on the length of BPM with the stress condition. The C-type string was manufactured and the spring force was measured as well.
E. Ayas, J.J. Casas, C. Colldelram, Ll. Fuentes, J. Iglesias, M. Quispe
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
This paper presents an investigation into the thermal instability problems that currently affect the ALBA Cooling System. During these periods of instabilities, which occur for a few hours every week of operation, there are deviations up to +1.5 °C, concerning the nominal temperature of 23 ± 0.2 °C in the four rings of ALBA: Service Area, Booster, Storage and Experimental Hall. This problem has a direct impact on the quality of the beam of the Accelerator. Previous studies have preliminarily concluded that the causes of this problem are due to (1) thermohydraulic anomalies in the operation of the external cogeneration plant, which supplies cold water to ALBA, and (2) cavitation problems in the pumping system (the water mass flow has been reduced to 67% of its nominal value to temporarily mitigate the cavitation). In order to confirm these hypotheses and propose solutions to the problem, an investigation has been developed making use of one-dimensional thermohydraulic simulations, performing Computational Fluid Dynamic (CFD) studies, statistical evaluations of data taken from our control system, and systematic flow measurements in critical areas, with ultrasonic flowmeters. As a result of this research, a set of solutions and recommendations are finally proposed to solve this problem.
K.J. Suthar, S. Sorsher, E. Trakhtenberg, A. Zholents
ANL, Lemont, Illinois, USA
Funding:This is based upon work supported by LDRD funding from Argonne National Laboratory, provided by the Director, Office of Science, of the U.S. Department of Energy under contract DE-AC02-06CH11357. The vacuum level in a 2 mm diameter, 0.5 m-long copper corrugated waveguide tube proposed* for a compact high repetition rate wakefield accelerator has been investigated. The analytical calculations have been found to be in good agreement with a result of computer modeling using a finite element method. A representative experiment has been conducted using a smooth copper tube with the same diameter as the corrugated tube and a 1/3 length of the corrugated tube. The vacuum level calculated for this experiment agrees well with the measurement. *A. Zholentset et al., inProc. 9th International Particle Accelerator Conference (IPAC’18), Vancouver, BC, Canada, 29 April-04 May 2018, ser. IPAC Conference, pp. 1266’1268.
P. Bado, M. Dugan, A.A. Said
Translume, Inc., Ann Arbor, Michigan, USA
A.E. Siy
UW-Madison, Madison, Wisconsin, USA
K.J. Suthar, A. Zholents
ANL, Lemont, Illinois, USA
Funding:This manuscript is based upon work supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-06CH11357 A cylindrical, corrugated wakefield accelerating (CWA) structure is being designed to facilitate sub-terahertz Cerenkov radiation produced by an electron bunch propagating in a waveguided structure comprising accelerating sections and transition sections*. The accelerating structure consists of several copper-based 50-cm long sections of internally corrugated tubes with 2-mm inner-diameter. These sections are coupled together using transition sections, which are also copper-based. The transition section has a main body diameter ranging from 2mm to 3.2mm and its length is about 14mm. Two sets of four orthogonal waveguides radiate from the central body. Beside their mechanical coupling function, these transition sections provide for periodic monitoring of the centering of the electron bunch, and for removal of unwanted higher-order EM modes. The fabrication of these transition sections is presented. The fabrication process is based on the use of a sacrificial fused silica glass mandrel, whose body corresponds to the inner volume of the copper element. This fused silica mandrel is subsequently electroplated. The micro-fabrication of a prototype of the transition section is underway. Modelling of various fabrication errors was undertaken to understand their effect and to determine tolerances. Source of machining imperfections are reviewed and their impact compared to the modelling results. *A. Zholents et al., "A conceptual design of a Compact Wakefield Accelerator for a high repetition rate multi user Xray Free-Electron Laser Facility," in Proc. 9th Int.l Particle Accel. Conf., 2018
J.L. Giorgetta, A. Lestrade, A. Mary, K. Tavakoli
SOLEIL, Gif-sur-Yvette, France
The current girder set of SOLEIL features 4 girder types weighing from 1.85 t to 3 t, with a respective mass payload varying from 4.1 t to 8 t and lengths from 2.40 m to 4.80 m. The smaller size of magnets used for the present version of the SOLEIL upgrade allows a dramatic size and weight reduction of the magnet-girder assemblies. On the other hand, the number of magnets and girders has increased by a factor of 3, implying longer alignment and installation operations. Another constraint is due to the high compactness of the new lattice causing some limitations and access restrictions in the area between girders and tunnel wall. Several setups involving a number of girders from 116 to 212, various magnet layouts and binding systems have been studied. Dynamic and thermal performances have been evaluated by FEA analysis. This approach gives to accelerator physicists the performance of each solution, and thus a great versatility in the choice of the best setup in terms of dynamic and thermal stability. Alignment constraints, installation schedule reducing "dark time" period and economic considerations have also been taken into account during all the design phase.
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The cavity is one of the main components of all accelerators, which is used to increase the energy level of charged particles (electrons, protons, etc.). The cavities increase the energy level of the charged particle by providing a suitable electric field to accelerate the charged particle. Here, information about electron beam welding analysis in 100 MHz cavities of ILSF design will be explained. According to studies performed in most accelerators in the world, connections in cavities are made by various methods such as explosive welding, brazing, electron beam welding, etc. Many articles on large cavities state that the connection of the side doors must be done by the electron beam welding process. However, in the present paper, the three-dimensional model of the cavity is imported into Simufact. Welding software after simplification and mesh process was done, and then the heat source of electron beam welding and other welding factors such as beam power, Gaussian distribution, etc. are applied in the software. The purpose of this study is the number of residual stresses during the EBW process in the 100 MHz cavity of ILSF.
G. Iori, M.M. Al Shehab, M.A. Al-Najdawi, A. Lausi
SESAME, Allan, Jordan
M. Altissimo, I. Cudin
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
A. Kaprolat, J. Reyes-Herrera, P. Van Vaerenbergh
ESRF, Grenoble, France
T. Kolodziej
NSRC SOLARIS, Kraków, Poland
Funding:EU H2020 framework programme for research and innovation. Grant agreement n°822535. The BEAmline for Tomography at SESAME (BEATS) will operate an X-rayμtomography station providing service to scientists from archaeology, cultural heritage, medicine, biology, material science and engineering, geology and environmental sciences*. BEATS will have a length of 45 m with a 3-pole-wiggler source (3 T peak magnetic field at 11 mm gap). Filtered white and monochromatic beam (8 keV to 50 keV, dE/E: 2% to 3% using a double-multilayer-monochromator) modalities will be available. In this work we present the beamline optical design, verified with simulation tools included in OASYS**. The calculated flux through 1 mm2 at the sample position will be as high as 8.5×109 Ph/s/mm2 in 0.1% of the source bandwidth, for a maximum usable beam size of 70×15 mm2. Beam transverse coherence will be limited to below 1 µm by the horizontal size of the X-ray source (~2 mm FWHM). For phase contrast applications requiring enhanced coherence, front end slits can be closed to 0.5 mm horizontally, with a reduction of the available beam size and photon flux. The BEATS beamline will fulfill the needs of the tomography community of SESAME. * H2020 project BEATS, Technical Design Report (July 2020). ** L. Rebuffi and M. Sanchez del Rio, Proc. SPIE 10388: 130080S (2017).
J.M. Álvarez, C. Colldelram, N González, J. Juanhuix, J. Nicolás, I. Šics
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
XAIRA, the hard X-ray microfocus beamline at ALBA, includes three monochromatic fluorescence screens and one water cooled white beam monitor in its layout, mounting respectively YAG:Ce and polycrystalline CVD diamond as scintillator screens. All monitors share the same design scheme, with a re-entrant viewport for the visualization system that allows reducing the working distance, as required for high magnification imaging. The scintillator screen assembly is held by the same CF63 flange, making the whole system very compact and stable. The re-entrant flange is driven by a stepper motor actuated linear stage that positions or retracts the screen with respect to the beam path. To cope with high power density (18, 6 W/m2) on the white beam monitor 100 µm-thick diamond screen, an InGa-based cooling system has been developed. The general design of the new fluorescence screens, to be used also in other ALBA’s upcoming beamlines, with particular detail on the water-cooled white beam monitor, is described here.
C.Y. Chang, C.F. Chang, C.H. Chang, S.H. Chang, L.C. Chiang, R. Lee, B.Y. Liao, C.Y. Liu
NSRRC, Hsinchu, Taiwan
We developed a white beam position detector to be applied in beamlines with bending magnets. By 0.1 mm light-receiving opening, the beam is split and converted to a photocurrent intensity which can be used to detect the size and position of the beam is less than or equal to 50 mm, and to locate the positions of the beamline components. This is a stop-beam measurement method, so it cannot be used to monitor the beam in real time. The motorized stage of the detector has a range of motion up to ± 25 mm with position accuracy not more than 1 micrometer and vacuum capability not more than 5 × 10 -10 Torr, which is compatible with ultra-high vacuum environments. In addition, taking the thermal load 62.89 W of the TPS 02A beamline as an example, the thermal deformation of the analog detector opening lead to a result that the measured value will have a maximum of 2 micrometer from the center of the beam. Finally, and the whole system has been successfully applied in the TPS 02A beamline.all features are verified and the performance meets the requirements, Besides the positioning tasks of Mask and Slits1 was completed and the position change of the light source was detected.
X. Li, X. Shen, R. Zwarich
CLS, Saskatoon, Saskatchewan, Canada
The Canadian Light Source Inc. (CLSI), opened in 2004 and located in Saskatoon, Saskatchewan, Canada, is a third-generation synchrotron light source facility with a 2.9 GeV storage ring. CLSI was built based on the Saskatchewan Accelerator Laboratory (SAL) with its LINAC. The SAL LINAC was built in 1960s and refurbished to operate at 250 MeV in 2002. It was also de-signed at an average beam power up to 46KW. To be used by CLS, the LINAC was modified for operation at pulse power levels of 25 MW with the current 100 mA. The modified LINAC consists of an electron gun and section 0 to 6, Energy Compression System (ECS) and Section 7. The LINAC has kept a steady performance throughout the years, along with many repairs and replacements ’ most of which are preventative. The original Varian type accelerating Sections are planned to be replaced gradual-ly by SLAC type Sections. Section 3 and 4 are two of the original 3 Varian type sections left in CLS - with over 55 years of service, they were accumulating vacuum leak problems from time to time. The replacement of Section 3 and 4 was completed in 2020. The mechanical consideration of the Section 3 and 4 replacement mainly includes upgrading supporting structures, designing Wave-guides, modifying LCW systems, getting solution to move the sections around in the LINAC tunnel, etc.
Tighter specifications in synchrotron instrumentation development force the design engineers more and more often to choose a mechatronics design approach. This includes actively controlled systems that need to be properly designed. The new Nano Active Stabilization System (NASS) for the ESRF beamline ID31 was designed with such an approach. We chose a multi-body design modelling approach for the development of the NASS end-station. Significance of such models depend strongly on its input and consideration of the right stiffness of the system’s components and subsystems. For that matter, we considered sub-components in the multi-body model as reduced order flexible bodies representing the component’s modal behaviour with reduced mass and stiffness matrices obtained from finite element analysis (FEA) models. These matrices were created from FEA models via modal reduction techniques, more specifically the component mode synthesis (CMS). This makes this design approach a combined multibody-FEA technique. We validated the technique with a test bench that confirmed the good modelling capabilities using reduced order flexible body models obtained from FEA for an amplified piezoelectric actuator (APA).
CFD Predictions of Water Flow Through Impellers of the ALBA Centrifugal Pumps and Their Aspiration Zone. An Investigation of Fluid Dynamics Effects on Cavitation Problems
J.J. Casas, C. Colldelram, M. Quispe
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
Currently, the ALBA refrigeration system pumps present cavitation when operating at their nominal regime. To alleviate this phenomenon temporarily until a definitive solution was found, the water flow was reduced to 67% of its nominal value. As this flow exchanges heat with the cooling water produced in an external cogeneration plant, modifying the working point of the pumps resulted in a reduction of the Accelerator cooling capacity. However, even at such low flow conditions, the flow has an anomalous oscillatory behaviour in the distributor of the aspiration zone, implying that the cause may be in a bad dimensioning of the manifold. This paper presents a study of Computational Fluid Dynamics (CFD) applied to the aspiration zones of the pumps, to investigate the effects of fluid dynamics on cavitation problems and understand what may be happening in the system. The need for such research arises from the urge to recover the accelerator cooling capacity and the constant pursuit for the improvement of the system. The geometries for this study include the general manifold in the aspiration zone and a simplified model of the pump impeller. The simulations have been carried out with the ANSYS-FLUENT software. Studies performed include considering the total water flow in nominal and under current operating conditions. In addition, the cases in which the flow is distributed through the manifold tubes in uniform and non-uniform ways have been treated separately. Pressure and velocity fields are analysed for various turbulence models. Finally, conclusions and recommendations to the problem are presented.
K.J. Suthar, S.H. Lee, S. Sorsher, E. Trakhtenberg, G.J. Waldschmidt, A. Zholents
ANL, Lemont, Illinois, USA
A.E. Siy
UW-Madison/PD, Madison, Wisconsin, USA
Funding:This work supported by Laboratory Directed Research and Development (LDRD) funding from Argonne, provided by the Director, Office of Science, of the U.S. DOE under contract DE-AC02-06CH11357. Thermal stresses generated due to the electromagnetic (EM) heating is a defining phenomenon in the mechanical design of the miniature copper-based corrugated wakefield accelerator (CWA). We investigate the effect of the EM heating due to the high repetition rate electron bunches traveling through a corrugated tube with 1-mm-inner-radius. The steady-state thermal analysis is coupled with computational fluid dynamics, and structural mechanics to determine the thermal effect on the operating conditions of CWA. It could carry a 10 nC drive bunch through the center of corrugated structure that generates a field gradient 100 Mv/m at 180 GHz, accelerating a trailing 0.3 nC witness bunch to 5 GeV. The wakefield produced by the traveling bunches can deposit about 600 W to 3000 W of energy on the inner wall of the device. Also, the instabilities in e-beam trajectories caused by thermal expansion, and the resulting stresses associated high-frequency repetition rate of 10 kHz to 50 kHz are the main concern for the waveguide. Tensile-yield failure due to moderate heating on the surface of the <200 micrometer wide trough regions of the corrugated tube may lead to arcing and loss of the wakefield.
P. Sanchez Navarro
DLS, Oxfordshire, United Kingdom
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. *Gilmore DG. Spacecraft thermal control handbook. Volume I, Volume I, [Internet]. 2002. Available from: http://app.knovel.com/hotlink/toc/id:kpSTCHVFT2/spacecraft-thermal-control
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F. Yang, D. La Civita, H. Sinn, M. Vannoni
EuXFEL, Hamburg, Germany
The European XFEL GmbH, located in Hamburg area in Germany, is the X-ray free electron laser light source which has been in the operation since 2017. It is designed to provide users high intensity X-ray beam with 27000 pulses/s repetition rate in the photon energy range from 0.5 to 25 keV*. In the beam transport system, the optic components which have direct contact with the beam, e.g. mirror, absorber and beam shutter, etc., could get up to 10 kW heat load on a sub-mm spot in 0.6 ms. Therefore, the thermo-mechanical performance of these optic components is playing an important role in the safety operation of the facility, restricting the maximum allowed beam power delivered to each experiment station. In this contribution, using finite element simulation tools, a parametric study about coupled thermo-mechanical behavior of some general used materials, e.g. CVD diamond, B4C, silicon, etc. is presented. Based on the design of several devices which are already in operation at European XFEL**, an initial damage threshold for these materials is established, with respect to the corresponding beam parameters. Furthermore, the relevant analytical and numerical solutions are discussed and compared, taking the material and geometrical nonlinearities into account. These simulation results can be referred as design and operation benchmark for the optic elements in the beamlines. *Altarelli, M. et al., The XFEL Technical Design Report, 2006. **Tschentscher, Th. et al., Photon Beam Transport and Scientific Instruments at the European XFEL, Applied Sciences 7(6):592, 2017.
S. Andresen
Alfred-Wegener-Institut, Bremerhaven, Germany
N. Meyners, D. Thoden
DESY, Hamburg, Germany
Funding:Deutsches Elektronen Synchrotron (DESY), a research centre of the Helmholtz Association - Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research DESY (Deutsches Elektronen Synchrotron) is currently expanding the PETRA III storage ring X-ray radiation source to a high-resolution 3D X-ray microscope providing all length scales from the atom to millimeters. This PETRA IV project involves an optimization of the girder magnet assemblies to reduce the impact of ambient vibrations on the particle beam. For this purpose, an innovative and biologically inspired girder structure has been developed. Beforehand, a large parametric study analyzed the impact of different loading and boundary conditions on the eigenfrequencies of a magnet-girder assembly. Subsequently, the girder design process was generated, which combined topology optimizations with biologically inspired structures (e.g., complex Voronoi combs, hierarchical structures, and smooth connections) and cross section optimizations using genetic algorithms to obtain a girder magnet assembly with high eigenfrequencies, a high stiffness, and reduced weight. The girder was successfully manufactured from gray cast iron and first vibration experiments have been conducted to validate the simulations.
