IPAC2018 - List of Authors (Power, J.F.)

Paper	Title	Page
TUYGBE3	Recent progress of short pulse dielectric two-beam acceleration	640
	J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, N.R. Neveu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	Two-Beam Acceleration (TBA) is a structure-based wakefield acceleration method with the potential to meet the luminosity and cost requirements of a TeV class linear collider. The Argonne Wakefield Accelerator (AWA) facility is developing a dielectric-based short pulse TBA scheme with the potential to withstand high acceleration gradients and to achieve low fabrication cost. Recently, the dielectric short pulse TBA technology was successfully demonstrated using K-band 26 GHz structures, achieving 55 MW output power from the power extractor and 28 MeV/m gradient in the accelerator. To improve the generated rf power, an X-band 11.7 GHz power extractor has been developed, which obtained 10⁵ MW in the high power test. In addition, a novel dielectric disk accelerator (DDA) is currently under investigation to significantly increase the efficiency of linear colliders based on short pulse TBA. Details of these research will be presented in this paper.
	Slides TUYGBE3 [2.219 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUYGBE3
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TUPML003	Design of an L-band Accelerating Structure for the Argonne Wakefield Accelerator Facility Witness Beam Line Energy Upgrade	1533
	J.H. Shao, M.E. Conde, D.S. Doran, J.F. Power ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	The Argonne Wakefield Accelerator (AWA) facility has been devoting much effort to the fundamental R&D of two-beam acceleration (TBA) technology with two parallel L-band beam lines. Beginning from the 70 MeV drive beam line, the high frequency (C-band and above) rf power is extracted from the beam by a decelerating structure (a.k.a. power extractor), transferred to an accelerating structure in the witness beam line, and used to accelerate the 15 MeV main beam. These high frequency accelerating structures usually have a small aperture to obtain high gradient and high efficiency, making it difficult for the low energy main beam to pass. To address this issue, one proposal is to increase the main beam energy to above 30 MeV by replacing the current witness linac. A 9-cell 𝜋-mode L-band standing-wave accelerating structure has therefore been designed to meet the high shunt impedance and low cost requirements. In addition, the single-feed coupling cell has been optimized with additional symmetrical ports to eliminate field distortion. The detailed design of the new accelerating structure will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML003
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TUPML005	Study of a Dielectric Disk Structure for Short Pulse Two-Beam Acceleration	1539
	J.H. Shao, M.E. Conde, D.S. Doran, J.F. Power ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	Argonne Flexible Linear Collider (AFLC), a proposed 3 TeV electron-positron linear collider based on two-beam acceleration (TBA) scheme, applies a short pulse length (∼20 ns) to obtain a high accelerating gradient (267 MV/m) and a compact footprint (∼18 km). The baseline design of the main accelerator section adopts 26 GHz K-band traveling-wave dielectric-loaded accelerators (DLA) with an rf to beam efficiency 𝜂𝑟𝑓 −𝑏𝑒𝑎𝑚 of 27%. Recently, an alternative structure which is similar to a metallic disk-loaded one but with dielectric disks, noted as dielectric disk accelerator (DDA), has been investigated and optimized, leading to ∼45% improvement in 𝜂𝑟𝑓 −𝑏𝑒𝑎𝑚. To demonstrate the key technologies, an X-band prototype structure has been designed and will be tested at Argonne Wakefield Accelerator (AWA) facility with a 300 MW metallic power extractor. Detailed comparison between K-band DLA and DDA for AFLC main accelerator as well as the preliminary design of the X-band DDA prototype will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML005
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TUPML006	Updates of the Argonne Cathode Test-stand	1542
	J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng ANL, Argonne, Illinois, USA S.P. Antipov, G. Chen, E. Gomez, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA S.V. Baryshev Michigan State University, East Lansing, Michigan, USA
	The Argonne Cathode Test-stand (ACT) is a unique testbed to develop cathodes and to conduct fundamental surface study under ultra-high rf field (up to 700 MV/m with pin-shaped cathodes). The test-stand consists of an L-band 1.3 GHz single-cell photocathode rf gun and a field emission (FE) imaging system to locate emitters with a resolution of ∼20 𝜇m. In the recent upgrade, UV laser has been introduced to improve the imaging system and to significantly expand the ACT towards photoemission and laser-assisted field emission research. In addition, a load-lock system has been added to the beam line to expedite the cathode switching period. The paper will present details of the upgrade as well as experiments planned in the near future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML006
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TUPML007	Short Pulse High Power RF Generation with an X-Band Dielectric Power Extractor	1546
	J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, N.R. Neveu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	Short pulse high power rf generation is one of the key technologies for the Argonne Flexible Linear Collider (AFLC), a proposed 3 TeV electron-positron linear collider based on two-beam acceleration (TBA) scheme. Compared with metallic power extractors, dielectric structures have the potential to achieve lower fabrication cost and to withstand higher gradient. Recently, an X-band dielectric power extractor (a.k.a, DPETS) has been developed at the Argonne Wakefield Accelerator (AWA) facility and achieved 10⁵ MW output power when driven by a high charge 8-bunch train separated by 770 ps. The design, the cold test measurement, the preliminary high power test results, and the structure inspection will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Recent progress of short pulse dielectric two-beam acceleration

640

J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, N.R. Neveu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

Two-Beam Acceleration (TBA) is a structure-based wakefield acceleration method with the potential to meet the luminosity and cost requirements of a TeV class linear collider. The Argonne Wakefield Accelerator (AWA) facility is developing a dielectric-based short pulse TBA scheme with the potential to withstand high acceleration gradients and to achieve low fabrication cost. Recently, the dielectric short pulse TBA technology was successfully demonstrated using K-band 26 GHz structures, achieving 55 MW output power from the power extractor and 28 MeV/m gradient in the accelerator. To improve the generated rf power, an X-band 11.7 GHz power extractor has been developed, which obtained 10⁵ MW in the high power test. In addition, a novel dielectric disk accelerator (DDA) is currently under investigation to significantly increase the efficiency of linear colliders based on short pulse TBA. Details of these research will be presented in this paper.

Slides TUYGBE3 [2.219 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUYGBE3

Export •

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

TUPML003

Design of an L-band Accelerating Structure for the Argonne Wakefield Accelerator Facility Witness Beam Line Energy Upgrade

1533

J.H. Shao, M.E. Conde, D.S. Doran, J.F. Power
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

The Argonne Wakefield Accelerator (AWA) facility has been devoting much effort to the fundamental R&D of two-beam acceleration (TBA) technology with two parallel L-band beam lines. Beginning from the 70 MeV drive beam line, the high frequency (C-band and above) rf power is extracted from the beam by a decelerating structure (a.k.a. power extractor), transferred to an accelerating structure in the witness beam line, and used to accelerate the 15 MeV main beam. These high frequency accelerating structures usually have a small aperture to obtain high gradient and high efficiency, making it difficult for the low energy main beam to pass. To address this issue, one proposal is to increase the main beam energy to above 30 MeV by replacing the current witness linac. A 9-cell 𝜋-mode L-band standing-wave accelerating structure has therefore been designed to meet the high shunt impedance and low cost requirements. In addition, the single-feed coupling cell has been optimized with additional symmetrical ports to eliminate field distortion. The detailed design of the new accelerating structure will be presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML003

Export •

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

TUPML005

Study of a Dielectric Disk Structure for Short Pulse Two-Beam Acceleration

1539

J.H. Shao, M.E. Conde, D.S. Doran, J.F. Power
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

Argonne Flexible Linear Collider (AFLC), a proposed 3 TeV electron-positron linear collider based on two-beam acceleration (TBA) scheme, applies a short pulse length (∼20 ns) to obtain a high accelerating gradient (267 MV/m) and a compact footprint (∼18 km). The baseline design of the main accelerator section adopts 26 GHz K-band traveling-wave dielectric-loaded accelerators (DLA) with an rf to beam efficiency 𝜂𝑟𝑓 −𝑏𝑒𝑎𝑚 of 27%. Recently, an alternative structure which is similar to a metallic disk-loaded one but with dielectric disks, noted as dielectric disk accelerator (DDA), has been investigated and optimized, leading to ∼45% improvement in 𝜂𝑟𝑓 −𝑏𝑒𝑎𝑚. To demonstrate the key technologies, an X-band prototype structure has been designed and will be tested at Argonne Wakefield Accelerator (AWA) facility with a 300 MW metallic power extractor. Detailed comparison between K-band DLA and DDA for AFLC main accelerator as well as the preliminary design of the X-band DDA prototype will be presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML005

Export •

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

TUPML006

Updates of the Argonne Cathode Test-stand

1542

J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng
ANL, Argonne, Illinois, USA
S.P. Antipov, G. Chen, E. Gomez, C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
S.V. Baryshev
Michigan State University, East Lansing, Michigan, USA

The Argonne Cathode Test-stand (ACT) is a unique testbed to develop cathodes and to conduct fundamental surface study under ultra-high rf field (up to 700 MV/m with pin-shaped cathodes). The test-stand consists of an L-band 1.3 GHz single-cell photocathode rf gun and a field emission (FE) imaging system to locate emitters with a resolution of ∼20 𝜇m. In the recent upgrade, UV laser has been introduced to improve the imaging system and to significantly expand the ACT towards photoemission and laser-assisted field emission research. In addition, a load-lock system has been added to the beam line to expedite the cathode switching period. The paper will present details of the upgrade as well as experiments planned in the near future.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML006

Export •

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

TUPML007

Short Pulse High Power RF Generation with an X-Band Dielectric Power Extractor

1546

J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, N.R. Neveu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

Short pulse high power rf generation is one of the key technologies for the Argonne Flexible Linear Collider (AFLC), a proposed 3 TeV electron-positron linear collider based on two-beam acceleration (TBA) scheme. Compared with metallic power extractors, dielectric structures have the potential to achieve lower fabrication cost and to withstand higher gradient. Recently, an X-band dielectric power extractor (a.k.a, DPETS) has been developed at the Argonne Wakefield Accelerator (AWA) facility and achieved 10⁵ MW output power when driven by a high charge 8-bunch train separated by 770 ps. The design, the cold test measurement, the preliminary high power test results, and the structure inspection will be presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML007

Export •

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