IPAC2015 - List of Authors (Harkay, K.C.)

Paper	Title	Page
TUPJE064	Calibration of Fast Fiber-Optic Beam Loss Monitors for the Advanced Photon Source Storage Ring Superconducting Undulators	1780
	J.C. Dooling, K.C. Harkay, Y. Ivanyushenkov, V. Sajaev, A. Xiao ANL, Argonne, Ilinois, USA A. Vella University of Illinois at Urbana-Champaign, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under contract number DE-AC02-06CH11357. We report on the calibration and use of fast fiber-optic (FO) beam loss monitors (BLMs) in the Advanced Photon Source storage ring (SR). A superconducting undulator prototype (SCU0) has been operating in SR Sector 6 since the beginning of CY2013, and another undulator SCU1 (a 1.1-m length undulator that is three times the length of SCU0) is scheduled for installation in Sector 1 in 2015. The SCU0 main coil often quenches during beam dumps. MARS simulations have shown that relatively small beam loss (<1 nC) can lead to temperature excursions sufficient to cause quenching when the SCU0 windings are near critical current. To characterize local beam losses, high-purity fused-silica FO cables were installed in Sector 6 next to the SCU0 cryostat and in Sector 1 where SCU1 will be installed. These BLMs aid in the search for operating modes that protect the SCU structures from beam-loss-induced quenching. In this paper, we describe the BLM calibration process that included deliberate beam dumps at locations of BLMs. We also compare beam dump events where SCU0 did and did not quench.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE064
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TUPJE066	Development of an Abort Kicker at APS to Mitigate Beam Loss-induced Quenches of the Superconducting Undulator	1787
	K.C. Harkay, J.C. Dooling, Y. Ivanyushenkov, R. Laird, F. Lenkszus, C.C. Putnam, V. Sajaev, J. Wang ANL, Argonne, Illinois, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The first superconducting undulator (SCU0) at the Advanced Photon Source (APS) has been delivering 80-100 keV photons for user science since January 2013. SCU0 often quenches during beam dumps triggered by the machine protection system (MPS). SCU0 typically recovers quickly after a quench, but SCU1, a second, longer device to be installed in 2015, may take longer to recover. We tested using injection kickers as an abort system to dump the beam away from SCU0 and the planned location of SCU1. An alternate trigger was tested that fires the kickers with MPS. We demonstrated that controlling the beam dump location with kickers can significantly reduce the beam losses at SCU0, as measured by fiber optic (FO) beam loss monitors (BLMs), and can also prevent a quench. A dedicated abort kicker system has been developed based on elegant simulations. A spare injection kicker was modified to produce the required waveform. Injection kicker tests, simulations, and the abort kicker design are described. Demonstration of this strategy in APS has implications for the APS Upgrade, where more SCUs are planned.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE066
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TUPJE068	Development and Performance of 1.1-m Long Superconducting Undulator at the Advanced Photon Source	1794
	Y. Ivanyushenkov, C.L. Doose, J.F. Fuerst, E. Gluskin, K.C. Harkay, Q.B. Hasse, M. Kasa, Y. Shiroyanagi, D. Skiadopoulos, E. Trakhtenberg ANL, Argonne, Ilinois, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. Development of superconducting undulators continues at the Advanced Photon Source (APS). The second superconducting undulator, SCU1, has been built and installed in the storage ring of the APS. This undulator has a 1.1-m long superconducting magnet and utilizes an improved version of the cryostat of the first superconducting undulator, SCU0. The results of the cold test of the SCU1, and its performance in the APS storage ring are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE068
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TUPJE079	High Charge Development of the APS Injector for an MBA Upgrade	1828
	C. Yao, M. Borland, J.R. Calvey, K.C. Harkay, D. Horan, R.R. Lindberg, N. Sereno, H. Shang, X. Sun, J. Wang ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The APS MBA (multi-bend achromat) upgrade storage ring will employ a “swap out” injection scheme and requires a single-bunch beam with up to 20 nC from the injector. The APS injector, which consists of a 450-MeV linac, a particle accumulator ring (PAR), and a 7-GeV synchrotron (Booster), was originally designed to provide up to 6 nC of beam charge. High charge injector study is part of the APS upgrade R&D that explores the capabilities and limitations of the injector through machine studies and simulations, and identifies necessary upgrades in order to meet the requirements of the MBA upgrade. In the past year we performed PAR and booster high charge studies, implemented new ramp correction of the booster rap supplies, explored non-linear chromatic correction of the booster, etc. This report presents the results and findings.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE079
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Paper

Title

Page

Calibration of Fast Fiber-Optic Beam Loss Monitors for the Advanced Photon Source Storage Ring Superconducting Undulators

1780

J.C. Dooling, K.C. Harkay, Y. Ivanyushenkov, V. Sajaev, A. Xiao
ANL, Argonne, Ilinois, USA
A. Vella
University of Illinois at Urbana-Champaign, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under contract number DE-AC02-06CH11357.
We report on the calibration and use of fast fiber-optic (FO) beam loss monitors (BLMs) in the Advanced Photon Source storage ring (SR). A superconducting undulator prototype (SCU0) has been operating in SR Sector 6 since the beginning of CY2013, and another undulator SCU1 (a 1.1-m length undulator that is three times the length of SCU0) is scheduled for installation in Sector 1 in 2015. The SCU0 main coil often quenches during beam dumps. MARS simulations have shown that relatively small beam loss (<1 nC) can lead to temperature excursions sufficient to cause quenching when the SCU0 windings are near critical current. To characterize local beam losses, high-purity fused-silica FO cables were installed in Sector 6 next to the SCU0 cryostat and in Sector 1 where SCU1 will be installed. These BLMs aid in the search for operating modes that protect the SCU structures from beam-loss-induced quenching. In this paper, we describe the BLM calibration process that included deliberate beam dumps at locations of BLMs. We also compare beam dump events where SCU0 did and did not quench.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE064

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TUPJE066

Development of an Abort Kicker at APS to Mitigate Beam Loss-induced Quenches of the Superconducting Undulator

1787

K.C. Harkay, J.C. Dooling, Y. Ivanyushenkov, R. Laird, F. Lenkszus, C.C. Putnam, V. Sajaev, J. Wang
ANL, Argonne, Illinois, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The first superconducting undulator (SCU0) at the Advanced Photon Source (APS) has been delivering 80-100 keV photons for user science since January 2013. SCU0 often quenches during beam dumps triggered by the machine protection system (MPS). SCU0 typically recovers quickly after a quench, but SCU1, a second, longer device to be installed in 2015, may take longer to recover. We tested using injection kickers as an abort system to dump the beam away from SCU0 and the planned location of SCU1. An alternate trigger was tested that fires the kickers with MPS. We demonstrated that controlling the beam dump location with kickers can significantly reduce the beam losses at SCU0, as measured by fiber optic (FO) beam loss monitors (BLMs), and can also prevent a quench. A dedicated abort kicker system has been developed based on elegant simulations. A spare injection kicker was modified to produce the required waveform. Injection kicker tests, simulations, and the abort kicker design are described. Demonstration of this strategy in APS has implications for the APS Upgrade, where more SCUs are planned.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE066

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TUPJE068

Development and Performance of 1.1-m Long Superconducting Undulator at the Advanced Photon Source

1794

Y. Ivanyushenkov, C.L. Doose, J.F. Fuerst, E. Gluskin, K.C. Harkay, Q.B. Hasse, M. Kasa, Y. Shiroyanagi, D. Skiadopoulos, E. Trakhtenberg
ANL, Argonne, Ilinois, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Development of superconducting undulators continues at the Advanced Photon Source (APS). The second superconducting undulator, SCU1, has been built and installed in the storage ring of the APS. This undulator has a 1.1-m long superconducting magnet and utilizes an improved version of the cryostat of the first superconducting undulator, SCU0. The results of the cold test of the SCU1, and its performance in the APS storage ring are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE068

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TUPJE079

High Charge Development of the APS Injector for an MBA Upgrade

1828

C. Yao, M. Borland, J.R. Calvey, K.C. Harkay, D. Horan, R.R. Lindberg, N. Sereno, H. Shang, X. Sun, J. Wang
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The APS MBA (multi-bend achromat) upgrade storage ring will employ a “swap out” injection scheme and requires a single-bunch beam with up to 20 nC from the injector. The APS injector, which consists of a 450-MeV linac, a particle accumulator ring (PAR), and a 7-GeV synchrotron (Booster), was originally designed to provide up to 6 nC of beam charge. High charge injector study is part of the APS upgrade R&D that explores the capabilities and limitations of the injector through machine studies and simulations, and identifies necessary upgrades in order to meet the requirements of the MBA upgrade. In the past year we performed PAR and booster high charge studies, implemented new ramp correction of the booster rap supplies, explored non-linear chromatic correction of the booster, etc. This report presents the results and findings.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE079

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