IPAC2019 - List of Authors (Powers, T.)

Paper	Title	Page
TUXXPLM2	SRF Cavity Fault Classification Using Machine Learning at CEBAF	1167
	A.D. Solopova, A. Carpenter, T. Powers, Y. Roblin, C. Tennant JLab, Newport News, Virginia, USA K.M. Iftekharuddin, L. Vidyaratne ODU, Norfolk, Virginia, USA
	The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is the first large high power CW recirculating electron accelerator which makes use of SRF accelerating structures configured in two antiparallel linacs. Each linac consists of twenty C20/C50 cryomodules each containing eight 5-cell cavities and five C100 upgrade cryomodules each containing eight 7-cell cavities. Accurately classifying the source of cavity faults is critical for improving accelerator performance. In addition to archived signals sampled at 10 Hz, a cavity fault triggers a waveform acquisition process where 16 waveform records sampled at 5 kHz are recorded for each of the 8 cavities in the effected cryomodule. The waveform record length is sufficiently long for transient microphonic effects to be observable. Significant time is required by a subject matter expert to analyze and identify the intra-cavity signatures of imminent faults. This paper describes a path forward that utilizes machine learning for automatic fault classification. Post-training identification of the physical origins of faults are discussed, as are potential machine-trained model-free implementations of trip avoidance procedures. These methods should provide new insights into cavity fault mechanisms and facilitate intelligent optimization of cryomodule performance
	Slides TUXXPLM2 [4.404 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUXXPLM2
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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WEPRB098	Cryogenic RF Performance of Double-Quarter Wave Cavities Equipped with HOM Filters	3043
	S. Verdú-Andrés, I. Ben-Zvi, Q. Wu, B.P. Xiao BNL, Upton, Long Island, New York, USA I. Ben-Zvi Stony Brook University, Stony Brook, USA G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom G. Burt, J.A. Mitchell Lancaster University, Lancaster, United Kingdom R. Calaga, O. Capatina CERN, Meyrin, Switzerland N.A. Huque, E.A. McEwen, H. Park, T. Powers JLab, Newport News, Virginia, USA Z. Li, A. Ratti SLAC, Menlo Park, California, USA
	Funding: Work supported by US DOE through BSA LLC under contracts No. DE-AC02-98CH10886, No. DE-SC0012704, and the US LHC Accelerator Research Program (LARP) and by the EU HL-LHC Project. Crab cavities are one of the several components included in the luminosity upgrade of the Large Hadron Collider (HL-LHC). The cavities have to provide a nominal deflecting kick of 3.4 MV per cavity while the cryogenic load per cavity stays below 5 W. Cold RF tests confirmed the required performances in bare cavities, with several cavities exceeding the required voltage by more than 50%. However, the first tests of a Double-Quarter Wave (DQW) cavity with one out of three HOM filters did not reach the required voltage. The present paper describes the studies and tests conducted on a DQW cavity with HOM filter to understand the limiting factor. The recipe to meet the performance specification and exceed the voltage requirement by more than 35% is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB098
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THXXPLM3	Experimental and Simulation Studies of Cooling of a Bunched Ion Beam in a Storage Ring by a Bunched Electron Beam
	Y. Zhang, S.V. Benson, A. Hutton, K. Jordan, T. Powers, R.A. Rimmer, M.F. Spata, A.V. Sy, H. Wang, S. Wang, H. Zhang JLab, Newport News, Virginia, USA J. Li, X.M. Ma, L.J. Mao, M.T. Tang, J.C. Yang, X.D. Yang, H. Zhao, H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China
	Cooling of a high energy ion beam is essential for future electron-ion colliders to reach high luminosity. It is critical to demonstrate experimentally cooling by a bunched electron beam and to benchmark the experimental data with simulations. Such experimental and simulation studies were carried out by a collaboration of Jefferson Lab and Institute of Modern Physics (IMP), utilizing a DC cooler at IMP. The thermionic gun of the DC cooler was modified by pulsing its grid voltage to produce cooling electron pulses in a pulse length range of 0.07 - 3.5 µs, with a 250 kHZ repetition frequency. The performed experiments clearly demonstrated cooling of a RF focused ion bunches by this pulsed electron beam. The momentum spread of cooled ion bunch has been reduced from ~2x10^-3 to ~6x10-4 in less than 0.5 second. The simulation results agree with the measurements qualitatively. In this paper, we present a brief overview of the experiments and also show the main experimental and simulation results.
	Slides THXXPLM3 [6.436 MB]
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Paper

Title

Page

SRF Cavity Fault Classification Using Machine Learning at CEBAF

1167

A.D. Solopova, A. Carpenter, T. Powers, Y. Roblin, C. Tennant
JLab, Newport News, Virginia, USA
K.M. Iftekharuddin, L. Vidyaratne
ODU, Norfolk, Virginia, USA

The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is the first large high power CW recirculating electron accelerator which makes use of SRF accelerating structures configured in two antiparallel linacs. Each linac consists of twenty C20/C50 cryomodules each containing eight 5-cell cavities and five C100 upgrade cryomodules each containing eight 7-cell cavities. Accurately classifying the source of cavity faults is critical for improving accelerator performance. In addition to archived signals sampled at 10 Hz, a cavity fault triggers a waveform acquisition process where 16 waveform records sampled at 5 kHz are recorded for each of the 8 cavities in the effected cryomodule. The waveform record length is sufficiently long for transient microphonic effects to be observable. Significant time is required by a subject matter expert to analyze and identify the intra-cavity signatures of imminent faults. This paper describes a path forward that utilizes machine learning for automatic fault classification. Post-training identification of the physical origins of faults are discussed, as are potential machine-trained model-free implementations of trip avoidance procedures. These methods should provide new insights into cavity fault mechanisms and facilitate intelligent optimization of cryomodule performance

Slides TUXXPLM2 [4.404 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUXXPLM2

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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

WEPRB098

Cryogenic RF Performance of Double-Quarter Wave Cavities Equipped with HOM Filters

3043

S. Verdú-Andrés, I. Ben-Zvi, Q. Wu, B.P. Xiao
BNL, Upton, Long Island, New York, USA
I. Ben-Zvi
Stony Brook University, Stony Brook, USA
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
G. Burt, J.A. Mitchell
Lancaster University, Lancaster, United Kingdom
R. Calaga, O. Capatina
CERN, Meyrin, Switzerland
N.A. Huque, E.A. McEwen, H. Park, T. Powers
JLab, Newport News, Virginia, USA
Z. Li, A. Ratti
SLAC, Menlo Park, California, USA

Funding: Work supported by US DOE through BSA LLC under contracts No. DE-AC02-98CH10886, No. DE-SC0012704, and the US LHC Accelerator Research Program (LARP) and by the EU HL-LHC Project.
Crab cavities are one of the several components included in the luminosity upgrade of the Large Hadron Collider (HL-LHC). The cavities have to provide a nominal deflecting kick of 3.4 MV per cavity while the cryogenic load per cavity stays below 5 W. Cold RF tests confirmed the required performances in bare cavities, with several cavities exceeding the required voltage by more than 50%. However, the first tests of a Double-Quarter Wave (DQW) cavity with one out of three HOM filters did not reach the required voltage. The present paper describes the studies and tests conducted on a DQW cavity with HOM filter to understand the limiting factor. The recipe to meet the performance specification and exceed the voltage requirement by more than 35% is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB098

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

THXXPLM3

Experimental and Simulation Studies of Cooling of a Bunched Ion Beam in a Storage Ring by a Bunched Electron Beam

Y. Zhang, S.V. Benson, A. Hutton, K. Jordan, T. Powers, R.A. Rimmer, M.F. Spata, A.V. Sy, H. Wang, S. Wang, H. Zhang
JLab, Newport News, Virginia, USA
J. Li, X.M. Ma, L.J. Mao, M.T. Tang, J.C. Yang, X.D. Yang, H. Zhao, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

Cooling of a high energy ion beam is essential for future electron-ion colliders to reach high luminosity. It is critical to demonstrate experimentally cooling by a bunched electron beam and to benchmark the experimental data with simulations. Such experimental and simulation studies were carried out by a collaboration of Jefferson Lab and Institute of Modern Physics (IMP), utilizing a DC cooler at IMP. The thermionic gun of the DC cooler was modified by pulsing its grid voltage to produce cooling electron pulses in a pulse length range of 0.07 - 3.5 µs, with a 250 kHZ repetition frequency. The performed experiments clearly demonstrated cooling of a RF focused ion bunches by this pulsed electron beam. The momentum spread of cooled ion bunch has been reduced from ~2x10^-3 to ~6x10-4 in less than 0.5 second. The simulation results agree with the measurements qualitatively. In this paper, we present a brief overview of the experiments and also show the main experimental and simulation results.

Slides THXXPLM3 [6.436 MB]

Export •

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