IPAC2015 - List of Authors (Kelly, M.P.)

Paper	Title	Page
TUPJE076	Design Study of the Higher Harmonic Cavity for Advanced Photon Source Upgrade	1819
	S.H. Kim, T.G. Berenc, J. Carwardine, G. Decker, M.P. Kelly, P.N. Ostroumov ANL, Argonne, Illinois, USA
	Funding: Results in this report are derived from work performed at Argonne National Laboratory. Argonne is operated by UChicago Argonne, LLC, for the U.S. Department of Energy under contract DE-AC02-06CH11357. A higher-harmonic cavity is planned for the proposed Advanced Photon Source (APS) multi-bend achromat (MBA) lattice to increase the bunch length, improve the Touschek lifetime and increase the single-bunch current limit. We have investigated a range of options including 3rd, 4th, and 5th harmonics of the main radio frequency (RF) system, as well as configurations with and without external RF power couplers. The current baseline is a single 4th harmonic superconducting cavity with adjustable RF couplers and a slow tuner which provide the flexibility to operate over a wide range of beam currents. The cavity is designed to provide 0.84 MV at 1408 MHz for the nominal 6 GeV, 200 mA electron beam, and 4.1 MV main RF voltage. In this paper, we discuss the harmonic cavity parameters based on analytical calculations of the equilibrium bunch distribution and make comparisons to other options.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE076
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WEPTY008	Superconducting Harmonic Cavity for the Advanced Photon Source Upgrade	3267
	M.P. Kelly, A. Barcikowski, J. Carwardine, Z.A. Conway, D. Horan, S.H. Kim, P.N. Ostroumov, G.J. Waldschmidt ANL, Argonne, Illinois, USA J. Rathke, T. Schultheiss AES, Medford, New York, USA
	A new bunch lengthening cryomodule using a single-cell ‘higher-harmonic’ superconducting cavity (HHC) based on the TESLA shape and operating at the 4th harmonic (1408 MHz) of the main RF is under development at Argonne. The system will be used to improve the Touschek lifetime and increase the single-bunch current limit in the upgraded multibend achromat lattice of the Advanced Photon Source electron storage ring. The 4 K cryomodule will fit within one half of a straight section, ~2.5 meters, of the ring. The system will use a pair of moveable 20 kW (each) CW RF power couplers to adjust the loaded Q and extract power from the beam. This will provide the flexibility to adjust the impedance presented to the beam and run at various beam currents. Higher-order modes (HOMs) induced by the circulating electron beam will be extracted along the beam axis and damped using a pair of room temperature beam line absorbers. Engineering designs and the prototyping status for the cavity, power couplers and HOM absorbers are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY008
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WEPTY009	Preservation of Quality Factor of Half Wave Resonator during Quenching in the Presence of Solenoid Field	3270
	S.H. Kim, D.M. Caldwell, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.W.T. MacDonald, P.N. Ostroumov, T. Reid ANL, Argonne, Illinois, USA
	Funding: This work was supported by the U.S. Department of energy, Offices of High-Energy Physics and Nuclear Physics, under Contract No. DE-AC02-76-CH03000 and DE-AC02-06CH11357. The Proton Improvement Plan II at FNAL relies upon a 162.5 MHz superconducting half-wave resonator cryomodule to accelerate H⁻ beams from 2.1 to 10 MeV. This cryomodule contains 8 resonators with 8 superconducting solenoid magnets interspersed between them. X-Y steering coils are integrated with a package of the superconducting solenoid magnets. The center of the solenoids is located within ~50 cm of the high surface magnetic field of the half-wave resonators and in this study we assess whether or not magnetic flux generated by this magnet is trapped into the half-wave resonators niobium surface and increases the RF losses to liquid helium. To test this we assembled a solenoid with a 162.5 MHz half-wave resonator spaced as they will be in the cryomodule. We measured the quality factor of the cavity before and after the cavity quenched as a function of field level in the coils. No measurable change in the quality factor was observed. In this paper, we will present details of the measurements and discuss the magnetic field map.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY009
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WEPTY010	Electropolishing for Low-Beta and Quasi-Waveguide SRF Cavities	3273
	T. Reid, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, P.N. Ostroumov ANL, Argonne, USA
	Argonne National Laboratory (ANL) has extended high quality electropolishing techniques based on those developed for the International Linear Collider to several more complex superconducting RF cavities. These include the co-axial TEM-mode quarter-wave and half-wave cavities as well as a 2.8 GHz quasi-waveguide structure intended for beam bunch rotation. This system is an improved version of the one developed for 1.3 GHz 9-cell cavities and includes easy provision for direct water cooling using the helium jacket. The performance of these SRF cavities both in terms of RF fields and losses equals or exceeds that of most 9-cell elliptical cavities built and tested today.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY010
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WEPWI051	Update on the CeC POP 704 MHz 5-Cell Cavity Cryomodule Design and Fabrication	3603
	J.C. Brutus, S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko, I. Pinayev, J. Skaritka, L. Snydstrup, R. Than, J.E. Tuozzolo, W. Xu BNL, Upton, Long Island, New York, USA S.M. Gerbick, M.P. Kelly, T. Reid ANL, Argonne, Illinois, USA T.L. Grimm, R. Jecks, J.A. Yancey Niowave, Inc., Lansing, Michigan, USA Y. Huang Fermilab, Batavia, Illinois, USA
	Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE. A 5-cell SRF cavity operating at 704 MHz will be used for the Coherent Electron Cooling Proof of Principle (CeC PoP) system currently under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the ability of relativistic electrons to cool a single bunch of heavy ions in RHIC. The cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up to 22 MeV. Novel mechanical designs, including the helium vessel, vacuum vessel, tuner mechanism, and FPC are presented. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for the CeC PoP experiment. .
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI051
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Paper

Title

Page

Design Study of the Higher Harmonic Cavity for Advanced Photon Source Upgrade

1819

S.H. Kim, T.G. Berenc, J. Carwardine, G. Decker, M.P. Kelly, P.N. Ostroumov
ANL, Argonne, Illinois, USA

Funding: Results in this report are derived from work performed at Argonne National Laboratory. Argonne is operated by UChicago Argonne, LLC, for the U.S. Department of Energy under contract DE-AC02-06CH11357.
A higher-harmonic cavity is planned for the proposed Advanced Photon Source (APS) multi-bend achromat (MBA) lattice to increase the bunch length, improve the Touschek lifetime and increase the single-bunch current limit. We have investigated a range of options including 3rd, 4th, and 5th harmonics of the main radio frequency (RF) system, as well as configurations with and without external RF power couplers. The current baseline is a single 4th harmonic superconducting cavity with adjustable RF couplers and a slow tuner which provide the flexibility to operate over a wide range of beam currents. The cavity is designed to provide 0.84 MV at 1408 MHz for the nominal 6 GeV, 200 mA electron beam, and 4.1 MV main RF voltage. In this paper, we discuss the harmonic cavity parameters based on analytical calculations of the equilibrium bunch distribution and make comparisons to other options.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE076

Export •

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

WEPTY008

Superconducting Harmonic Cavity for the Advanced Photon Source Upgrade

3267

M.P. Kelly, A. Barcikowski, J. Carwardine, Z.A. Conway, D. Horan, S.H. Kim, P.N. Ostroumov, G.J. Waldschmidt
ANL, Argonne, Illinois, USA
J. Rathke, T. Schultheiss
AES, Medford, New York, USA

A new bunch lengthening cryomodule using a single-cell ‘higher-harmonic’ superconducting cavity (HHC) based on the TESLA shape and operating at the 4th harmonic (1408 MHz) of the main RF is under development at Argonne. The system will be used to improve the Touschek lifetime and increase the single-bunch current limit in the upgraded multibend achromat lattice of the Advanced Photon Source electron storage ring. The 4 K cryomodule will fit within one half of a straight section, ~2.5 meters, of the ring. The system will use a pair of moveable 20 kW (each) CW RF power couplers to adjust the loaded Q and extract power from the beam. This will provide the flexibility to adjust the impedance presented to the beam and run at various beam currents. Higher-order modes (HOMs) induced by the circulating electron beam will be extracted along the beam axis and damped using a pair of room temperature beam line absorbers. Engineering designs and the prototyping status for the cavity, power couplers and HOM absorbers are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY008

Export •

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

WEPTY009

Preservation of Quality Factor of Half Wave Resonator during Quenching in the Presence of Solenoid Field

3270

S.H. Kim, D.M. Caldwell, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.W.T. MacDonald, P.N. Ostroumov, T. Reid
ANL, Argonne, Illinois, USA

Funding: This work was supported by the U.S. Department of energy, Offices of High-Energy Physics and Nuclear Physics, under Contract No. DE-AC02-76-CH03000 and DE-AC02-06CH11357.
The Proton Improvement Plan II at FNAL relies upon a 162.5 MHz superconducting half-wave resonator cryomodule to accelerate H⁻ beams from 2.1 to 10 MeV. This cryomodule contains 8 resonators with 8 superconducting solenoid magnets interspersed between them. X-Y steering coils are integrated with a package of the superconducting solenoid magnets. The center of the solenoids is located within ~50 cm of the high surface magnetic field of the half-wave resonators and in this study we assess whether or not magnetic flux generated by this magnet is trapped into the half-wave resonators niobium surface and increases the RF losses to liquid helium. To test this we assembled a solenoid with a 162.5 MHz half-wave resonator spaced as they will be in the cryomodule. We measured the quality factor of the cavity before and after the cavity quenched as a function of field level in the coils. No measurable change in the quality factor was observed. In this paper, we will present details of the measurements and discuss the magnetic field map.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY009

Export •

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

WEPTY010

Electropolishing for Low-Beta and Quasi-Waveguide SRF Cavities

3273

T. Reid, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, P.N. Ostroumov
ANL, Argonne, USA

Argonne National Laboratory (ANL) has extended high quality electropolishing techniques based on those developed for the International Linear Collider to several more complex superconducting RF cavities. These include the co-axial TEM-mode quarter-wave and half-wave cavities as well as a 2.8 GHz quasi-waveguide structure intended for beam bunch rotation. This system is an improved version of the one developed for 1.3 GHz 9-cell cavities and includes easy provision for direct water cooling using the helium jacket. The performance of these SRF cavities both in terms of RF fields and losses equals or exceeds that of most 9-cell elliptical cavities built and tested today.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY010

Export •

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

WEPWI051

Update on the CeC POP 704 MHz 5-Cell Cavity Cryomodule Design and Fabrication

3603

J.C. Brutus, S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko, I. Pinayev, J. Skaritka, L. Snydstrup, R. Than, J.E. Tuozzolo, W. Xu
BNL, Upton, Long Island, New York, USA
S.M. Gerbick, M.P. Kelly, T. Reid
ANL, Argonne, Illinois, USA
T.L. Grimm, R. Jecks, J.A. Yancey
Niowave, Inc., Lansing, Michigan, USA
Y. Huang
Fermilab, Batavia, Illinois, USA

Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE.
A 5-cell SRF cavity operating at 704 MHz will be used for the Coherent Electron Cooling Proof of Principle (CeC PoP) system currently under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the ability of relativistic electrons to cool a single bunch of heavy ions in RHIC. The cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up to 22 MeV. Novel mechanical designs, including the helium vessel, vacuum vessel, tuner mechanism, and FPC are presented. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for the CeC PoP experiment.
.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI051

Export •

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