F. Cianciosi, A.-L. Buisson, P. Tafforeau, P. Van Vaerenbergh
ESRF, Grenoble, France
BM18 is an ESRF-EBS beamline for hierarchical tomography, it will combine sub-micron precision and the possibility to scan very large samples. The applications will include biomedical imaging, material sciences and cultural heritage. It will allow the complete scanning of a post-mortem human body at 25 µm, with the ability to zoom-in in any location to 0.7 µm. BM18 is exploiting the high-energy-coherence beam of the new EBS storage ring. The X-ray source is a short tripole wiggler that gives a 300mm-wide beam at the sample position placed 172m away from the source. Due to this beam size, nearly all of the instruments are devel-oped in-house. A new building was constructed to ac-commodate the largest synchrotron white-beam Experi-mental Hutch worldwide (42x5-6m). The main optical components are refractive lenses, slits, filters and a chop-per. There is no crystal monochromator present but the combination of the optical elements will provide high quality filtered white beams, as well as an inline mono-chromator system. The energy will span from 25 to 350 keV. The Experimental Hutch is connected by a 120m long UHV pipe with a large window at the end, followed by a last set of slits. The sample stage can position, rotate and monitor with sub-micron precision samples up to 2,5x0.6m (H x Diam.) and 300kg. The resulting machine is 4x3x5m and weighs 50 tons. The girder for detectors carries up to 9 detectors on individual 2-axis stages. It moves on air-pads on a precision marble floor up to 38m behind the sample stage to perform phase contrast imag-ing at a very high energy on large objects. The commissioning is scheduled for the beginning of 2022; the first ’friendly users’ are expected in March 2022 and the full operation will start in September 2022.
A. Crisol, F. Bisti, C. Colldelram, M.L. Llonch, B. Molas, R. Monge, J. Nicolás, L. Nikitina, M. Quispe, L. Ribó, M. Tallarida
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
LOREA beamline (BL20) at ALBA Synchrotron is a new soft X-Ray beamline dedicated to investigate electronic structure of solids by means ARPES technique. Optical design has been developed in-house so as most of beamline core opto-mechanics like Monochromator. The design made for LOREA is based on a Hettrick-Underwood grating type that operates without entrance slit. Experience cumulated over years allowed to face the challenge of designing and building UHV Monochromator. The large energy range of LOREA (10-100 eV) requires a device with 3 mirrors and 4 gratings with variable line spacing to reduce aberrations. Monochromator most important part, gratings system, has been carefully designed to be isolated from external disturbances as cooling water, and at the same time having high performances. Deep analytical calculations and FEA simulations have been carried out, as well as testing prototypes. The most innovative part of Monochromator is gratings cooling with no vacuum guards or double piping that are well-known source of troubles. Heat load is removed by copper straps in contact with a temperature controller device connected to fixed water lines. In addition, motion mechanics and services (cabling, cooling) are independent systems. Designs involved give high stability (resonance modes over 60Hz) and angular resolution below 0.1 µrad over 11° range. On mirrors side, it has been used gonio mechanics from MIRAS* plus an eutectic InGa interface between cooling and optics to decouple them. Grating and mirror holders are fully removable from main mechanics to be able to assembled at lab measuring to achieve the best fit. Instrument has been already assembled and motions characterization or stability measurements are giving expected results matching with specifications. * L. Ribó et al., "MECHANICAL DESIGN OF MIRAS, INFRARED MICROSPECTROSCOPY BEAM LINE AT ALBA SYNCHROTRON", presented at MEDSI’16, Barcelona, Spain, September 2016, doi:10.18429/JACoW-MEDSI2016-FRAA03
Right click on video for Picture-in-Picture mode or Full screen display.
W.F. Sheng, H. Liang, Y.S. Lu, Z. Zhang
IHEP, Beijing, People’s Republic of China
Funding:This research is supported by National Natural Science Foundation of China (NSFC) (No.11905243). The stability of beamline optics directly affects the beamline’s performances, such as coherence, focal size, position stability of the beam and so on, it has become a serious issue for a low emittance 4th generation light source. The vibration transmitting function of supports plays a big role in the stability performance of the optics. In order to find out a stable supporting structure, several types of support structures were tested, and the transfer ratio were described. The result shows that wedge struc-tures generally have a lower transfer ratio, and point contact support structures should be avoided.
B.K. Popovic, S.H. Lee, S. Sorsher, K.J. Suthar, E. Trakhtenberg, G.J. Waldschmidt, A. Zholents
ANL, Lemont, Illinois, USA
A.E. Siy
UW-Madison, Madison, Wisconsin, USA
Funding:This manuscript is based upon work supported by Laboratory Directed Research and Development (LDRD) funding from Argonne National Laboratory This paper outlines the design of a diamond vacuum window and a millimeter wavelength (mmWave) waveguide assembly that will hold vacuum but still allow the mmWaves to propagate out of the structure for diagnosis and thermal management purposes. Currently under development at Argonne is a corrugated wakefield accelerator (CWA) that will operate at mmWave frequencies, with its fundamental mode of operation at 180 GHz, and relatively high power levels, up to 600 W. The fundamental mode needs to be extracted from the accelerator at approximately every 0.5 m to prevent the unwanted heating of the accelerator structure. Therefore, the structure is intentionally designed so this fundamental mode does not propagate further, instead it is transmitted through the waveguide assembly under vacuum and out via the vacuum window. As a result of the relatively high mmWave power densities, CVD diamond was chosen as the vacuum window material, due to its low electromagnetic losses, mechanical strength, and for its superior thermo-physical properties. Mechanically it is necessary to be able to hold the tight tolerances necessary for windows performance at millimeter wavelengths. Other mechanical difficulties involve assembly of the window due to CVD diamond material and preservation of ultra high vacuum even if the integrity of the CVD diamond window is somehow compromised.
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
K.J. Suthar, G. Navrotski, A. Zholents
ANL, Lemont, Illinois, USA
P.R. Carriere
RadiaBeam, Santa Monica, California, USA
Funding:Work supported by Laboratory Directed Research and Development funding from Argonne National Laboratory, provided by the Director, Office of Science, of the US DOE under contract DE-AC02-06CH11357. Fabrication of the corrugated structure that generates a field gradient 100 m-1 at 180 GHz is challenging and required an unconventional method of production. The corrugated waveguide with 2 mm inner diameter will be produced by electroplating copper on the aluminum mandrel as proposed in the reference*. A thin seed layer is usually applied to achieve uniform wetting to plate copper on the aluminum mandrel. The copper waveguide is retrieved by removing aluminum and the seed layer. Therefore, uniform copper plating and etching of the seed layer and the Aluminum mandrel is a crucial step to keep the surface free of impurities that are especially necessary for the RF application. Previous studies suggest that electroplated copper has variations in both electrical and mechanical properties compared with those of bulk copper from the batches of production. In this paper, we discuss the copper microstructure produced by the electroforming method and literature study on the variations, which can be attributed to the disparity of the crystallinity of grains structure in plated material. *A. Zholentset al., "A Conceptual Design of a Compact Wakefield Accelerator for a High Repetition Rate Multi-User X-ray Free-Electron Laser Facility, "in Proc. IPAC 18, 2018, pp. 1266-1268.
L.R.M. Ribó, D. Alloza, C. Colldelram, J. Nicolás, I. Šics
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
The ALBA optics laboratory has recently acquired a new Zygo Verifire HD Fizeau interferometer. The instrument has been integrated into a positioning stage to allow stitching of long x-ray optical elements. The mechanical set up, with four axes, allows for automatic positioning and alignment of the interferometer aperture to the surface under test. The longitudinal movement allows for scan of X-ray mirrors up to 1500 m long. The positioning platform includes two angles, roll and yaw, and two translations, vertical and longitudinal translations. The longitudinal translation is a custom designed linear stage. The yaw rotation is based on a sine arm mechanism. The vertical and roll motions are combined in a single stage, closely integrated around the main linear stage. The system reaches repeatabilities better than 1 µm or 1 µrad for all axes. The system is mounted on top of a vibration isolated bench in the clean room of the laboratory. The control software of the instrument allow direct control of every individual axis, and allows selecting the center of rotation for both roll and yaw. The system includes inclinometers and autocollimators to control the relative orientation between the interferometer and the mirror under test. The system is integrated to the software of the interferometer, and includes features for automatic alignment of the interferometer to the mirror, or for automatic stitching acquisition, with selectable parameters. The system allows for full three-dimensional characterization of the optical surface of mirrors and gratings, and provides height map reconstructions with accuracy in the order of 1 nm, for flat or curved surfaces with lengths up to 1500 mm.
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.
A. Crisol, A. Carballedo, C. Colldelram, N González, J. Juanhuix, J. Nicolás, L.R.M. Ribó, C. Ruget
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
L.W.S. Adamson
ASCo, Clayton, Victoria, Australia
J.B. González Fernández
MAX IV Laboratory, Lund University, Lund, Sweden
E.R. Jane
FMB Oxford, Oxford, United Kingdom
During the ALBA design phase, the protein macromolecular protein crystallography beamline, XALOC, required several in-house developments. The major part of these designs was at the end station where the necessity of customization is always much higher. The most relevant of these instruments was the beam conditioning elements table [1]. This accurate stage, which supports the diffractometer as well, includes the four movements required to align the components to the nominal beam as well as position the diffractometer. This design compacts, especially the vertical and pitch movements, both in a single stage, with a couple of stages for all four excursions. The solution maximise the stiffness and preserves at the same time the resolution close to 0.1µm while being able to withstand a half tone of payload. Thanks this compactness and performances this design concept, the vertical and pitch combined stage, was not only applied at XALOC for its diffractometer and detector table, but it has been widely adapted at several ALBA beamlines: at NCD-SWEET [2] as a detector table, a beam conditioning elements table [3] and sample table, at MSPD beamline as the KB table, at NOTOS beamline as metrology table, and also at the new ESA MINERVA beamline [4] for their sample mirror modules positioning. Beamlines have not been the only beneficiaries of this design, also different kind of instrumentation like an hall probe measuring bench [5], and even a stitching platform for the ALBA optics laboratory [6]. Moreover, the concept has outreach ALBA and has been adopted also at other facilities worldwide, synchrotrons and also scientific instrumentation suppliers around Europe. This poster presents most of the applications of the skin concept and their variations and main measured performances.
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.
S.H. Lee, W.G. Jansma, S. Sorsher, K.J. Suthar, E. Trakhtenberg, G.J. Waldschmidt, A. Zholents
ANL, Lemont, Illinois, USA
A.E. Siy
UW-Madison/PD, Madison, Wisconsin, USA
Funding:Work support by Laboratory Directed Research and Development funding from Argonne National Lab, by the Director, Office of Science, of the U.S. Department of Energy under contract DE-AC02-06CH11357. An effort to build Argonne’s Sub-THz AcceleRator (A-STAR) for a future multiuser x-ray free-electron laser facility proposed in [1] is underway at Argonne National Laboratory. The A-STAR machine will utilize a compact collinear wakefield accelerator (CWA) assembled in modules. To extract the wakefield and monitor beam position downstream of each module, a 45-mm-long transition section (TS) has been proposed and designed. This paper will discuss the design and fabrication chal-lenges for production of the TS. *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. IPAC’18, Canada, 2018, pp. 1266-1268.
S.H. Lee, D.S. Doran, W.G. Jansma, S. Sorsher, K.J. Suthar, E. Trakhtenberg, G.J. Waldschmidt, A. Zholents
ANL, Lemont, Illinois, USA
A.E. Siy
UW-Madison/PD, Madison, Wisconsin, USA
Funding:Work supported by Laboratory Directed Research and Development from Argonne National Lab, provided by the Director, Office of Science, of the U.S. Department of Energy under contract DE-AC02-06CH11357 Argonne National Laboratory is developing a Sub-THz AcceleRator (A-STAR) for a future multiuser x-ray free electron laser facility. The A-STAR machine will utilize a compact collinear wakefield accelerator (CWA) based on a miniature copper (Cu) corrugated waveguide as proposed*. The accelerator is designed to operate at a 20-kHz bunch repetition rate and will utilize the 180-GHz wakefield of a 10-nC electron drive bunch with a field gradient of 100 MVm’1 to accelerate a 0.3-nC electron witness bunch to 5 GeV. In this paper, we discuss specific challenges in the mechanical design of the CWA vacuum chamber module. The module consists of series of small quadrupole magnets with a high magnetic field gradient that houses a 2-mm diameter and 0.5-m-long corrugated tubing with brazed water-cooling channels and a transition section. The 45-mm-long transition section is used to extract the wakefield and to house a beam position monitor, a bellows assembly and a port to connect a vacuum pump. The CWA vacuum chamber module requires four to five brazing steps with filler metals of successively lower temperatures to maintain the integrity of previously brazed joints. *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. IPAC’18, Canada, 2018, pp. 1266~1268.
A compact sample furnace was designed and tested at the X-ray Powder Diffraction (XPD) beamline at NSLS-II. This furnace is designed to heat small samples to temperatures of 2000 - 2300°C while allowing the XPD photon beam to pass through with adequate downstream opening in the furnace to collect diffraction data. Since the XPD samples did not reach the desired temperatures initially, engineering studies, tests, and incremental improvements were planned and undertaken to improve performance. The design of the sample furnace will be presented as background, and engineering details will be presented in this paper describing work undertaken to improve the furnace design to allow sample temperatures to reach 2000 - 2300°C or more.
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.
C.A. Preissner, S.J. Bean, M. Erdmann
ANL, Lemont, Illinois, USA
M. Bergeret, J.R. Nasiatka
LBNL, Berkeley, California, USA
Funding:Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Engineers at the APS have developed a granite, air-bearing stage concept that provides many millimeters of motion range and nanometer-level vibrational stability. This technique was first conceptualized and used on the Velociprobe x-ray microscope. The success of that design spurred adaption of the approach to over 90 devices, including many new instruments at the APS and high performing instruments at other synchrotrons. This paper details the design concept, some performance measurements, and new developments allowing for a six-degree-of-freedom device.
S.J. Bean, S. Chen, T. Graber, C. Jacobsen, B. Lai, E.R. Maxey, T. Mooney, C.A. Preissner, X. Shi, D. Shu, J. Tan, W. Wojcik
ANL, Lemont, Illinois, USA
Funding:Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No.DE-AC02-06CH11357 The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) is being upgraded to a multi-bend achromat (MBA) lattice storage ring which will increase brightness and coherent flux by several orders of magnitude. As part of this upgrade a total of 15 beamlines were selected to be enhanced to take advantage of the new source ’ these are designated as ’Enhanced Beamlines’. Among these is the enhancement to 2-ID, which includes an upgrade and move of the existing Bionanoprobe (BNP) from 9-ID [1]. This instrument will become the second generation Bionanoprobe II (BNP-II) with intent of studying cryogenic samples with sub-10 nm resolution. This upgrade requires a high performing metrology configuration and design to achieve the desired spatial resolution while adapting to the various constraints of the instrument. The cryogenic sample environment and detection constraints offer significant challenges for implementing a metrology scheme. In this paper we report on the new traveling interferometer configuration proposed for BNP-II.
