SRF2019 - List of Authors (Conway, Z.A.)

Paper	Title	Page
TUFUB5	Effects of Static Magnetic Fields on a Low-frequency TEM Class Superconducting Cavity	370
	M.K. Ng, Z.A. Conway, M.P. Kelly, K.W. Shepard ANL, Lemont, Illinois, USA
	Systematic studies on the effect of magnetic fields on a 330 MHz superconducting (TEM-mode) half-wave cavity are presented. The practical application of the results is for a possible future 2 K operation in the ATLAS heavy-ion accelerator at Argonne. The low frequency and the integral stainless steel jacket, rather than titanium, provide important new data for this full production model low-beta cavity. The studies include multi-axial magnetic field measurements near the cavity surface due to ambient and applied fields. Cavity performance under different conditions is measured at temperatures ranging between 1.6 K and 4.5 K. A residual resistance of approximately 5-7 nΩ at 1.6 K is observed. Data suggest that an appreciable fraction arises from losses that are not due to flux trapping.
	Slides TUFUB5 [1.195 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUFUB5
About •	paper received ※ 24 June 2019 paper accepted ※ 14 August 2019 issue date ※ 14 August 2019
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TUP016	Quarter-wave Resonator with the Optimized Shape for Quantum Information Systems	430
	S.V. Kutsaev, R.B. Agustsson, P.R. Carriere, A. Moro, A.Yu. Smirnov, K.V. Taletski RadiaBeam, Santa Monica, California, USA A.N. Cleland, É. Dumur The University of Chicago, Chicago, Illinois, USA Z.A. Conway ANL, Lemont, Illinois, USA K.V. Taletski MEPhI, Moscow, Russia
	Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics, under SBIR grant DE-SC0018753 Quantum computers (QC), if realized, could disrupt many computationally intense fields of science. The building block element of a QC is a quantum bit (qubit). Qubits enable the use of quantum superposition and multi-state entanglement in QC calculations, allowing a QC to simultaneously calculate millions of computations at once. However, quantum states stored in a qubit degrade with decreased quality factors and interactions with the environment. One technical solution to improve qubit lifetimes and network interactions is a circuit comprised of a Josephson junction located inside of a high Q-factor superconducting 3D cavity. RadiaBeam, in collaboration with Argonne National Laboratory and The University of Chicago, has developed a superconducting radio-frequency quarter-wave resonant cavity (QWR) for quantum computation. Here a 6 GHz QWR was optimized to include tapering of the inner and outer conductors, a toroidal shape for the resonator shorting plane, and the inner conductor to reduce parasitic capacitance. In this paper, we present the results of the qubit cavity design optimization, fabrication, processing and testing in a single-photon regime at mK temperatures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP016
About •	paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
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TUP018	New SRF Structures Processed at the ANL Cavity Processing Facility	434
	T. Reid, Z.A. Conway, B.M. Guilfoyle, M. Kedzie, M.P. Kelly, M.K. Ng ANL, Lemont, Illinois, USA
	Argonne National Laboratory (ANL) has extended high quality cavity processing techniques based on those developed for the International Linear Collider to several more complex superconducting RF cavities. Recently, these include a bunch lengthening harmonic cavity, a crabbing rf-dipole cavity, a compact half-wave cavity, and both medium and high frequency elliptical cavities. These systems are an improved version of the one originally developed for 1.3 GHz 9-cell cavities and include a second rotating electrical contact that can support multiple cathodes, necessary for optimum polishing in difficult cavity geometries. All include the possibility for external water cooling.
	Poster TUP018 [4.322 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP018
About •	paper received ※ 28 June 2019 paper accepted ※ 12 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP102	Superconducting Harmonic Cavity for Bunch Lengthening in the APS Upgrade	715
	M.P. Kelly, Z.A. Conway, M. Kedzie, S.W.T. MacDonald, T. Reid, U. Wienands, G.P. Zinkann ANL, Lemont, Illinois, USA
	A superconducting cavity based Bunch Lengthening System is under construction for the Argonne’s Advanced Photon Source (APS) Upgrade. The system will reduce the undesirable effects of Touschek scattering on the beam lifetime by providing bunch lengthening in the longitudinal direction by 2-4 times. The major technical components for the beam-driven 1.4 GHz fourth harmonic superconducting cryomodule are in hand and have been tested. These include a superconducting cavity, cw rf power couplers, a pneumatic cavity slow tuner and beamline higher-order mode absorbers. Initial assembly and engineering testing of the cryomodule is underway. Final integrated testing will be complete in 2021. Transportation to and commissioning in the APS is planned for 2022-23.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP102
About •	paper received ※ 08 July 2019 paper accepted ※ 12 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Effects of Static Magnetic Fields on a Low-frequency TEM Class Superconducting Cavity

370

M.K. Ng, Z.A. Conway, M.P. Kelly, K.W. Shepard
ANL, Lemont, Illinois, USA

Systematic studies on the effect of magnetic fields on a 330 MHz superconducting (TEM-mode) half-wave cavity are presented. The practical application of the results is for a possible future 2 K operation in the ATLAS heavy-ion accelerator at Argonne. The low frequency and the integral stainless steel jacket, rather than titanium, provide important new data for this full production model low-beta cavity. The studies include multi-axial magnetic field measurements near the cavity surface due to ambient and applied fields. Cavity performance under different conditions is measured at temperatures ranging between 1.6 K and 4.5 K. A residual resistance of approximately 5-7 nΩ at 1.6 K is observed. Data suggest that an appreciable fraction arises from losses that are not due to flux trapping.

Slides TUFUB5 [1.195 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUFUB5

About •

paper received ※ 24 June 2019 paper accepted ※ 14 August 2019 issue date ※ 14 August 2019

Export •

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

TUP016

Quarter-wave Resonator with the Optimized Shape for Quantum Information Systems

430

S.V. Kutsaev, R.B. Agustsson, P.R. Carriere, A. Moro, A.Yu. Smirnov, K.V. Taletski
RadiaBeam, Santa Monica, California, USA
A.N. Cleland, É. Dumur
The University of Chicago, Chicago, Illinois, USA
Z.A. Conway
ANL, Lemont, Illinois, USA
K.V. Taletski
MEPhI, Moscow, Russia

Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics, under SBIR grant DE-SC0018753
Quantum computers (QC), if realized, could disrupt many computationally intense fields of science. The building block element of a QC is a quantum bit (qubit). Qubits enable the use of quantum superposition and multi-state entanglement in QC calculations, allowing a QC to simultaneously calculate millions of computations at once. However, quantum states stored in a qubit degrade with decreased quality factors and interactions with the environment. One technical solution to improve qubit lifetimes and network interactions is a circuit comprised of a Josephson junction located inside of a high Q-factor superconducting 3D cavity. RadiaBeam, in collaboration with Argonne National Laboratory and The University of Chicago, has developed a superconducting radio-frequency quarter-wave resonant cavity (QWR) for quantum computation. Here a 6 GHz QWR was optimized to include tapering of the inner and outer conductors, a toroidal shape for the resonator shorting plane, and the inner conductor to reduce parasitic capacitance. In this paper, we present the results of the qubit cavity design optimization, fabrication, processing and testing in a single-photon regime at mK temperatures.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP016

About •

paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

TUP018

New SRF Structures Processed at the ANL Cavity Processing Facility

434

T. Reid, Z.A. Conway, B.M. Guilfoyle, M. Kedzie, M.P. Kelly, M.K. Ng
ANL, Lemont, Illinois, USA

Argonne National Laboratory (ANL) has extended high quality cavity processing techniques based on those developed for the International Linear Collider to several more complex superconducting RF cavities. Recently, these include a bunch lengthening harmonic cavity, a crabbing rf-dipole cavity, a compact half-wave cavity, and both medium and high frequency elliptical cavities. These systems are an improved version of the one originally developed for 1.3 GHz 9-cell cavities and include a second rotating electrical contact that can support multiple cathodes, necessary for optimum polishing in difficult cavity geometries. All include the possibility for external water cooling.

Poster TUP018 [4.322 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP018

About •

paper received ※ 28 June 2019 paper accepted ※ 12 July 2019 issue date ※ 14 August 2019

Export •

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

TUP102

Superconducting Harmonic Cavity for Bunch Lengthening in the APS Upgrade

715

M.P. Kelly, Z.A. Conway, M. Kedzie, S.W.T. MacDonald, T. Reid, U. Wienands, G.P. Zinkann
ANL, Lemont, Illinois, USA

A superconducting cavity based Bunch Lengthening System is under construction for the Argonne’s Advanced Photon Source (APS) Upgrade. The system will reduce the undesirable effects of Touschek scattering on the beam lifetime by providing bunch lengthening in the longitudinal direction by 2-4 times. The major technical components for the beam-driven 1.4 GHz fourth harmonic superconducting cryomodule are in hand and have been tested. These include a superconducting cavity, cw rf power couplers, a pneumatic cavity slow tuner and beamline higher-order mode absorbers. Initial assembly and engineering testing of the cryomodule is underway. Final integrated testing will be complete in 2021. Transportation to and commissioning in the APS is planned for 2022-23.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP102

About •

paper received ※ 08 July 2019 paper accepted ※ 12 July 2019 issue date ※ 14 August 2019

Export •

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