NAPAC2022 - Table of Session: THYE (Accelerator Technology)

Paper	Title	Page
THYE1	Overview of Superconducting Magnet Technologies
	S.O. Prestemon LBNL, Berkeley, California, USA
	Very high field superconducting magnets represent a critical technology for future accelerators, high field user magnets, and energy applications such as magnetic fusion and wind turbines. We discuss exciting technical developments in the field and the national and international communities efforts to organize R&D to advance the field.
	Slides THYE1 [12.687 MB]
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THYE2	Development of Short-Period Nb₃Sn Superconducting Planar Undulators at the Advanced Photon Source
	I. Kesgin ANL, Lemont, Illinois, USA
	Superconducting technology has enabled the development of short-period undulators for higher-brightness X-rays at synchrotron light sources. Superconducting undulators (SCUs) hold great promise for XFELs as well. All operational devices are currently Nb Ti-based. Nb₃Sn has the potential to further enhance the performance of SCUs. This paper will describe the technical challenges and progress to date of this technology.
	Slides THYE2 [2.436 MB]
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THYE3	Superconducting Undulators and Cryomodules for X-ray Free-Electron Lasers	870
	D.C. Nguyen, G.J. Bouchard, B.M. Dunham, G.L. Gassner, Z. Huang, E.M. Kraft, P. Krejcik, M.A. Montironi, H.-D. Nuhn, T.O. Raubenheimer, Z.R. Wolf, Z. Zhang SLAC, Menlo Park, California, USA J.M. Byrd, J.D. Fuerst, E. Gluskin, Y. Ivanyushenkov, M. Kasa, E.R. Moog, M.F. Qian, Y. Shiroyanagi ANL, Lemont, Illinois, USA
	Funding: Work supported by the US DOE Office of Science, Basic Energy Sciences, Office of Accelerator and Detector Research (Manager: Dr. Eliane Lessner). We present connectable designs of superconducting undulators (SCU) and cryomodules (CM) based on previous SCU and CM designs at Argonne National Lab. The new SCU and CM designs will allow us to connect one CM to the next to form a contiguous line of SCUs with no breaks between the cryomodules. The SCU design will have correctors and phase shifters integrated into the main SCU magnet core, as well as external corrector magnets for trajectory corrections. There will also be a cryogenic magnetic quadrupole and a cold RF beam position monitor (BPM) integrated in the SCU CM. In addition to providing the usual FODO transverse focusing, the quadrupole and BPM will be used for the beam-based alignment technique that is critical for X-ray FEL operation. In this paper, we will present the conceptual design of the new SCU CM as well as results of FEL simulations using the SCUs as afterburners for the LCLS hard X-ray undulators.
	Slides THYE3 [2.657 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE3
About •	Received ※ 02 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 16 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYE4	Development of an Ultra-Low Vibration Cryostat Based on a Closed-Cycle Cryocooler	874
	R.W. Roca Illinois Institute of Technology, Chicago, Illinois, USA E.W. Knight, R.A. Kostinpresenter, Y. Zhao Euclid TechLabs, Solon, Ohio, USA
	Low temperature and low vibration cryostats are useful in a variety of applications such as x-ray diffraction, quantum computing, x-ray monochromators and cryo-TEMs. In this project, we explore an ultra-low vibration cryostat with the cooling provided by a closed cycle cryocooler. Closed-cycle cryocoolers inevitably introduce vibrations into the system, and in this project, flexible copper braiding was used to decouple vibrations and provide cooling at the same time. In order to develop the cryostat, capacity map of a two stage Sumitomo cryocooler was measured as well as vibration transmission through different copper braids using an IR interferometer. This paper covers the capacity map and vibration measurements in the first prototype.
	Slides THYE4 [4.989 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE4
About •	Received ※ 16 July 2022 — Revised ※ 10 August 2022 — Accepted ※ 20 August 2022 — Issue date ※ 12 September 2022
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THYE5	Analysis of Low RRR SRF Cavities	877
	K. Howard, Y.K. Kim University of Chicago, Chicago, Illinois, USA D. Bafia, A. Grassellino Fermilab, Batavia, Illinois, USA
	Recent findings in the superconducting radio-frequency (SRF) community have shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. Success has been found in nitrogen-doping, diffusion of the native oxide into the niobium surface, and thin films of alternate superconductors atop a niobium bulk cavity. We question why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurity profile of niobium with a low residual resistance ratio (RRR) and correlate these impurities with the RF performance of low RRR cavities so that the mechanism of recent impurity-based improvements can be better understood and improved upon. Additionally, we performed surface treatments, low temperature baking and nitrogen-doping, on low RRR cavities to evaluate how the intentional addition of more impurities to the RF layer affects performance. We have found that low RRR cavities experience low temperature-dependent BCS resistance behavior more prominently than their high RRR counterparts. The results of this study have the potential to unlock a new understanding on SRF materials.
	Slides THYE5 [5.013 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE5
About •	Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 01 October 2022
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THYE6	First Demonstration of a ZrNb Alloyed Surface for Superconducting Radio-Frequency Cavities	881
	Z. Sun, M. Liepe, T.E. Oseroff Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Surface design of the RF surface is a promising path to next-generation SRF cavities. Here, we report a new strategy based on ZrNb surface alloying. Material development via an electrochemical process will be detailed. RF performance evaluated in the Cornell sample host cavity will be discussed. Cornell demonstrates that ZrNb alloying is a viable new technology to improve the performance of SRF cavities.
	Slides THYE6 [1.459 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE6
About •	Received ※ 22 July 2022 — Accepted ※ 08 August 2022 — Issue date ※ 20 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

THYE1

Overview of Superconducting Magnet Technologies

S.O. Prestemon
LBNL, Berkeley, California, USA

Very high field superconducting magnets represent a critical technology for future accelerators, high field user magnets, and energy applications such as magnetic fusion and wind turbines. We discuss exciting technical developments in the field and the national and international communities efforts to organize R&D to advance the field.

Slides THYE1 [12.687 MB]

Cite •

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

THYE2

Development of Short-Period Nb₃Sn Superconducting Planar Undulators at the Advanced Photon Source

I. Kesgin
ANL, Lemont, Illinois, USA

Superconducting technology has enabled the development of short-period undulators for higher-brightness X-rays at synchrotron light sources. Superconducting undulators (SCUs) hold great promise for XFELs as well. All operational devices are currently Nb Ti-based. Nb₃Sn has the potential to further enhance the performance of SCUs. This paper will describe the technical challenges and progress to date of this technology.

Slides THYE2 [2.436 MB]

Cite •

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

THYE3

Superconducting Undulators and Cryomodules for X-ray Free-Electron Lasers

870

D.C. Nguyen, G.J. Bouchard, B.M. Dunham, G.L. Gassner, Z. Huang, E.M. Kraft, P. Krejcik, M.A. Montironi, H.-D. Nuhn, T.O. Raubenheimer, Z.R. Wolf, Z. Zhang
SLAC, Menlo Park, California, USA
J.M. Byrd, J.D. Fuerst, E. Gluskin, Y. Ivanyushenkov, M. Kasa, E.R. Moog, M.F. Qian, Y. Shiroyanagi
ANL, Lemont, Illinois, USA

Funding: Work supported by the US DOE Office of Science, Basic Energy Sciences, Office of Accelerator and Detector Research (Manager: Dr. Eliane Lessner).
We present connectable designs of superconducting undulators (SCU) and cryomodules (CM) based on previous SCU and CM designs at Argonne National Lab. The new SCU and CM designs will allow us to connect one CM to the next to form a contiguous line of SCUs with no breaks between the cryomodules. The SCU design will have correctors and phase shifters integrated into the main SCU magnet core, as well as external corrector magnets for trajectory corrections. There will also be a cryogenic magnetic quadrupole and a cold RF beam position monitor (BPM) integrated in the SCU CM. In addition to providing the usual FODO transverse focusing, the quadrupole and BPM will be used for the beam-based alignment technique that is critical for X-ray FEL operation. In this paper, we will present the conceptual design of the new SCU CM as well as results of FEL simulations using the SCUs as afterburners for the LCLS hard X-ray undulators.

Slides THYE3 [2.657 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE3

About •

Received ※ 02 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 16 August 2022

Cite •

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

THYE4

Development of an Ultra-Low Vibration Cryostat Based on a Closed-Cycle Cryocooler

874

R.W. Roca
Illinois Institute of Technology, Chicago, Illinois, USA
E.W. Knight, R.A. Kostinpresenter, Y. Zhao
Euclid TechLabs, Solon, Ohio, USA

Low temperature and low vibration cryostats are useful in a variety of applications such as x-ray diffraction, quantum computing, x-ray monochromators and cryo-TEMs. In this project, we explore an ultra-low vibration cryostat with the cooling provided by a closed cycle cryocooler. Closed-cycle cryocoolers inevitably introduce vibrations into the system, and in this project, flexible copper braiding was used to decouple vibrations and provide cooling at the same time. In order to develop the cryostat, capacity map of a two stage Sumitomo cryocooler was measured as well as vibration transmission through different copper braids using an IR interferometer. This paper covers the capacity map and vibration measurements in the first prototype.

Slides THYE4 [4.989 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE4

About •

Received ※ 16 July 2022 — Revised ※ 10 August 2022 — Accepted ※ 20 August 2022 — Issue date ※ 12 September 2022

Cite •

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

THYE5

Analysis of Low RRR SRF Cavities

877

K. Howard, Y.K. Kim
University of Chicago, Chicago, Illinois, USA
D. Bafia, A. Grassellino
Fermilab, Batavia, Illinois, USA

Recent findings in the superconducting radio-frequency (SRF) community have shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. Success has been found in nitrogen-doping, diffusion of the native oxide into the niobium surface, and thin films of alternate superconductors atop a niobium bulk cavity. We question why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurity profile of niobium with a low residual resistance ratio (RRR) and correlate these impurities with the RF performance of low RRR cavities so that the mechanism of recent impurity-based improvements can be better understood and improved upon. Additionally, we performed surface treatments, low temperature baking and nitrogen-doping, on low RRR cavities to evaluate how the intentional addition of more impurities to the RF layer affects performance. We have found that low RRR cavities experience low temperature-dependent BCS resistance behavior more prominently than their high RRR counterparts. The results of this study have the potential to unlock a new understanding on SRF materials.

Slides THYE5 [5.013 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE5

About •

Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 01 October 2022

Cite •

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

THYE6

First Demonstration of a ZrNb Alloyed Surface for Superconducting Radio-Frequency Cavities

881

Z. Sun, M. Liepe, T.E. Oseroff
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Surface design of the RF surface is a promising path to next-generation SRF cavities. Here, we report a new strategy based on ZrNb surface alloying. Material development via an electrochemical process will be detailed. RF performance evaluated in the Cornell sample host cavity will be discussed. Cornell demonstrates that ZrNb alloying is a viable new technology to improve the performance of SRF cavities.

Slides THYE6 [1.459 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE6

About •

Received ※ 22 July 2022 — Accepted ※ 08 August 2022 — Issue date ※ 20 August 2022

Cite •

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