Keyword: electron
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MOOA02 Experience with the Vacuum System for the First Fourth Generation Light Source: MAX IV vacuum, storage-ring, operation, synchrotron 10
 
  • E. Al-Dmour, M.J. Grabski, K. Åhnberg
    MAX IV Laboratory, Lund University, Lund, Sweden
  
  The 3 GeV electron storage ring of the MAX IV laboratory is the first storage-ring-based synchrotron radiation facility with small aperture and with the inner surface of almost all the vacuum chambers along its circumference coated with non-evaporable getter (NEG) thin film. This concept implies challenges during the whole project phase from design into operation. The fast conditioning of the vacuum system and over five years of reliable accelerator operation have demonstrated that the chosen design proved to be good and does not impose limits on the operation. A summary of the vacuum system design, production, installation and performance is presented.  
slides icon Slides MOOA02 [3.706 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-MOOA02  
About • paper received ※ 29 July 2021       paper accepted ※ 30 August 2021       issue date ※ 30 October 2021  
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MOPC05 Beamline Alignment and Characterization with an Autocollimator alignment, vacuum, synchrotron, photon 62
 
  • M.V. Fisher, A.A. Khan, J.J. Knopp
    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.
An electronic autocollimator is a valuable tool that can assist in the alignment of optical beamline components such as mirrors and monochromators. It is also a powerful tool for in situ diagnoses of the mechanical behavior of such components. This can include the repeatability of crystals, gratings, and mirrors as they are rotated; the parasitic errors of these same optical elements as they are rotated and/or translated; and the repeatability and parasitic errors as bendable mirrors are actuated. The autocollimator can even be used to establish a secondary reference if such components require servicing. This paper will provide examples of such alignments, diagnoses, and references that have been made with an autocollimator on existing and recently commissioned beam-lines at the Advanced Photon Source (APS). In addition, this paper will discuss how this experience influenced the specifications and subsequent designs of the new primary high-heat-load mirror systems (PHHLMS) that are currently under fabrication for six of the APS Up-grade (APS-U) feature beamlines. Each mirror was specified to provide in situ line-of-sight access for an autocollimator to either the center of the mirror’s optical surface or to a smaller polished surface centered on the backside of each mirror substrate. This line of sight will be used for initial alignment of the mirror and will be available for in situ diagnoses if required in the future. 		 
poster icon Poster MOPC05 [8.944 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-MOPC05  
About • paper received ※ 06 August 2021       paper accepted ※ 13 October 2021       issue date ※ 09 November 2021  
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MOPC11 Discrete Photon Absorbers for the APS-Upgrade Storage Ring Vacuum System photon, vacuum, storage-ring, interface 75
 
  • O.K. Mulvany, B. Billett, B. Brajuskovic, J.A. Carter, A. McElderry, R.R. Swanson
    ANL, Lemont, Illinois, USA
  
  Funding: This work is supported by the U.S. Department of Energy, Office of Science under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source Upgrade storage ring arc vacuum system features a diverse set of photon beam-intercepting components, including five discrete photon absorbers and a series of small-aperture vacuum chambers that shadow downstream components. The discrete photon absorbers, typically fabricated from electron beam-welded GlidCop AL-15, are subject to heat loads ranging from approximately 170 to 3400 watts, with a peak power density up to approximately 610 W/mm2 at normal incidence. Four of the five photon absorber designs are housed in vacuum chambers, including three that are mounted to the antechambers of curved aluminum extrusion-based L-bend vacuum chambers and one that is mounted to a stainless steel vacuum-pumping cross. Furthermore, two of the photon absorbers that are mounted to L-bend vacuum chambers are equipped with position-adjustment mechanisms, which are necessitated by the challenging design and fabrication of the curved vacuum chambers. The fifth photon absorber, unlike the rest, is a brazed design that is integral in sealing the vacuum system and intercepts approximately 170 watts. Each photon absorber design was optimized with thermal-structural finite element analyses while ensuring functional and spatial requirements were met. Some of these requirements include meeting internal high-heat-load component design criteria, respecting challenging component interfaces and alignment requirements, and minimizing impedance effects. Furthermore, photon beam scattering effects called for the use of scattering shields on three designs to minimize potential heating of vacuum chambers. This paper details the careful balance of functionality and manufacturability, and the overall design process followed to achieve the final designs. 		 
poster icon Poster MOPC11 [8.305 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-MOPC11  
About • paper received ※ 19 July 2021       paper accepted ※ 13 October 2021       issue date ※ 01 November 2021  
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TUOA02 Conceptual Design of the Cavity Mechanical System for Cavity-Based X-Ray Free Electron Laser FEL, cavity, vacuum, laser 103
 
  • D. Shu, J.W.J. Anton, L. Assoufid, W.G. Jansma, S.P. Kearney, K.-J. Kim, R.R. Lindberg, S.T. Mashrafi, X. Shi, Yu. Shvyd’ko, W.F. Toter, M. White
    ANL, Lemont, Illinois, USA
  • H. Bassan, F.-J. Decker, G.L. Gassner, Z. Huang, G. Marcus, H.-D. Nuhn, T.-F. Tan, D. Zhu
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract DE-AC02-06CH1 1357 (ANL) and DE-AC02-76SF00515 (SLAC).
The concept behind the cavity-based X-ray FELs (CBXFELs) such as the X-ray free-electron laser oscillator (XFELO)* and the X-ray regenerative amplifier free-electron laser (XRAFEL)** is to form an X-ray cavity with a set of narrow bandwidth diamond Bragg crystals. Storing and recirculating the output of an amplifier in an X- ray cavity so that the X-ray pulse can interact with following fresh electron bunches over many passes enables the development of full temporal coherence. One of the key challenges to forming the X-ray cavity is the precision of the cavity mechanical system design and construction. In this paper, we present conceptual design of the cavity mechanical system that is currently under development for use in a proof-of-principle cavity-based X-ray free electron laser experiment at the LCLS-II at SLAC.
*Kwang-Je Kim et al., TUPRB096, Proceedings of IPAC2019
**Gabe Marcus et al., TUD04, Proceedings of IPAC2019
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-TUOA02  
About • paper received ※ 02 August 2021       paper accepted ※ 05 October 2021       issue date ※ 30 October 2021  
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TUOA03 Zero-Length Conflat Fin-Type Nonevaporable Getter Pump Coated with Oxygen-Free Palladium/Titanium vacuum, ECR, site, power-supply 107
 
  • Y. Sato
    Yokohama National University, Graduate School of Engineering Science, Yokohama, Japan
  • A.H. Hashimoto, M. Yamanaka
    NIMS, Tsukuba, Ibaraki, Japan
  • T. Kikuchi, K. Mase
    KEK, Tsukuba, Japan
  • T. Miyazawa
    Sokendai, The Graduate University for Advanced Studies, Tsukuba, Japan
  • S. Ohno
    Yokohama National University, Yokohama, Japan
  
  Funding: This work was partly supported by a JSPS KAKENHI (JP19K05280), a TIA-Kakehashi (TK19-035), and the 2019 Takahashi Industrial Economic Research Foundation grant, and was supported by NIMS TEM Station.
We have developed a zero-length conflat fin-type nonevaporable getter (NEG) pump that uses oxygen-free palladium/titanium (Pd/Ti)*. After baking at 150 degrees centigrade for 12 h, the pumping speeds of the NEG pump for H2 and CO were 2350~800 L/s and 1560~20 L/s, respectively, in the pumped-quantity range 0.01~30 Pa L. The morphologies of oxygen-free Pd/Ti films on the partition plates and the base plate were examined by scanning electron microscopy, scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The Ti was completely coated with Pd on the bottom, whereas the partition plates were covered by Pd/Ti nanostructures. Our new NEG pump is ideal for maintaining ultrahigh vacuums in the range 10-8 to 10-9 Pa, because (a) its pumping speeds for H2 and CO are quite large, (b) it can evacuate H2O and CO2 when an ionization gauge is used in the vacuum system, (3) it can be activated by baking at 150 degrees centigrade for 12 h, (c) its pumping speed does not decrease even after 9 cycles of pumping, baking, cooling to room temperature, and exposure to air**, (5) it requires neither a dedicated power supply nor electric feedthroughs, and (6) it is space saving and lightweight.
*T. Miyazawa et al., J. Vac. Sci. Technol. A 36, 051601 (2018).
**T. Kikuchi et al., AIP Conf. Proc. 2054, 060046 (2019).
 		 
slides icon Slides TUOA03 [1.643 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-TUOA03  
About • paper received ※ 30 July 2021       paper accepted ※ 14 October 2021       issue date ※ 08 November 2021  
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TUPB08 High-Precision Synchrotron Kappa Diffractometer detector, synchrotron, alignment, synchrotron-radiation 163
 
  • G. Olea, N. Huber, J. Zeeb
    HUBER Diffraktiontechnik GmbH&Co.KG, Rimsting, Germany
  
  A new research product aiming to work in a 3th generation synchrotron facility (PAL/PLS II) has been developed. Based on increased energy X-ray synchrotron radiation tool and well-known Kappa geometry device principle, the product is expected that will investigate atomic and molecular structures of materials at nanoscale level using several X-ray diffraction techniques. The Kappa diffractometer (K-Dm) machine is maintaining the common structural principle of its family, but working with an extreme precision and load, which is far of the competition. The main body is consisting from customized Kappa goniometer (KGm) device with vertical axis of rotation for high-precision sample (cryostat) manipulation, versatile detector arm (Da) for manipulating in horizontal plan different detectors (optics, slits, etc.) after X-ray beam is scattered and stable alignment base (Ab) for roughly adjusting the product around the X-ray beam. In addition, a XYZ cryo-carrier inside of the KGm is included for fine (submicron) sample adjustments. The kinematic, design and precision concepts applied, together with the obtained test results are all in detail presented.*
* HUBER Diffraction and Positioning GmbH&Co.KG, https://www.xhuber.com/en/ 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-TUPB08  
About • paper received ※ 16 July 2021       paper accepted ※ 16 October 2021       issue date ※ 28 October 2021  
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TUPC01 Study of Copper Microstructure Produced by Electroforming for the 180-GHz Frequency Corrugated Waveguide GUI, ECR, wakefield, site 178
 
  • 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. 		 
poster icon Poster TUPC01 [1.717 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-TUPC01  
About • paper received ※ 21 July 2021       paper accepted ※ 05 November 2021       issue date ※ 06 November 2021  
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TUPC06 A Review of Ultrasonic Additive Manufacturing for Particle Accelerator Applications controls, embedded, electronics, interface 185
 
  • J.A. Brandt
    Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
  
  Additive manufacturing (AM) technologies have been used for prototyping and production parts in many industries. However, due to process limitations and the unknown material properties of AM parts, there has been limited adoption of the technology in accelerator and light-source facilities. Ultrasonic Additive Manufacturing (UAM) is a hybrid additive-subtractive manufacturing process that uses a solid-state ultrasonic bonding mechanism attached to a CNC mill to join and machine metal parts in a layer-by-layer manner. The solid-state and hybrid nature of UAM ensures base material properties are retained and mitigates process limitations which traditionally inhibit integration of parts produced by other AM processes. This paper presents a review of the UAM process and its potential application to accelerator and beamline needs. Several specific areas are discussed including: replacement of traditional manufacturing approaches, such as explosion bonding to join dissimilar metals; improved internal cooling channel fabrication for thermal management; and imbedding of electronics and materials for more accurate remote sensing and radiation shielding.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-TUPC06  
About • paper received ※ 22 July 2021       paper accepted ※ 16 October 2021       issue date ※ 05 November 2021  
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WEPA08 Investigating of EBW Process Weldment Connections Stresses in ILSF 100 MHz Cavity by Simufact. Welding Software cavity, software, vacuum, simulation 239
 
  • V. Moradi
    ILSF, Tehran, Iran
  • A. Adamian, N.B. Arab
    PPRC, Tehran, Iran
  
  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.  
poster icon Poster WEPA08 [2.344 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-WEPA08  
About • paper received ※ 21 July 2021       paper accepted ※ 19 October 2021       issue date ※ 02 November 2021  
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WEPB05 Mechanical Design of a Compact Collinear Wakefield Accelerator vacuum, GUI, wakefield, quadrupole 276
 
  • 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. 		 
poster icon Poster WEPB05 [1.316 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-WEPB05  
About • paper received ※ 14 July 2021       paper accepted ※ 16 October 2021       issue date ※ 28 October 2021  
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WEPB17 A Fast Simulation Tool to Calculate Spectral Power Density Emitted by Wigglers and Short Insertion Devices wiggler, photon, SRF, radiation 303
 
  • J. Reyes-Herrera, M. Sanchez del Rio
    ESRF, Grenoble, France
  
  The analysis of thermal stress of beamline components requires a comprehensive determination of the absorbed power profile. Consequently, accurate calculations of beam power density and its dependency on the photon energy are required. There exist precise tools to perform these calculations for undulator sources, like several methods available in the OASYS toolbox* considering, for example, the contribution of the different harmonics of the undulator radiation or using ray-tracing algorithms**. This is not the case for wiggler sources, in particular for short insertion devices that are used as source for the bending magnet beamlines in some upgraded storage rings like the ESRF-EBS. Wiggler radiation is incoherent and although it is possible the use of undulator methods for calculating it, this is very inefficient. In this work, we describe a tool that performs fast calculations of spectral power density from a wiggler source. The emission is calculated starting from a tabulated magnetic field and computes the power spatial and spectral density. It uses concepts inspired from Tanaka’s work***. It is implemented in a user-friendly widget in OASYS and can be connected to widgets to calculate absorbed and transmitted power density along the beamline components. The accuracy of the method is verified by calculating three examples and comparing the results with ray-tracing. The three insertion devices simulated are: the EBS-ESRF-3PW, the ESRF W150 (a high power wiggler) and the 3PW for the BEATS project at the SESAME synchrotron source.
*L. Rebuffi, M. Sanchez del Rio, Proc. SPIE 10388: 130080S (2017).
**L. Rebuffi et al., J Synchrotron Rad, 27, 1108-1120 (2020).
***T. Tanaka, H. Kitamura, AIP Conference Proceedings 705, 41 (2004). 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-WEPB17  
About • paper received ※ 28 July 2021       paper accepted ※ 28 September 2021       issue date ※ 09 November 2021  
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THIO02 Determination of Maximum Repetition Rate of a Corrugated-Waveguide-Based Wakefield Accelerator GUI, wakefield, simulation, radiation 336
 
  • 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. 		 
slides icon Slides THIO02 [16.639 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-THIO02  
About • paper received ※ 21 July 2021       paper accepted ※ 06 October 2021       issue date ※ 27 October 2021  
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