NAPAC2016 - List of Authors (Wang, J.)

Paper	Title	Page
MOPOB12	A High Bandwidth Bipolar Power Supply for the Fast Correctors in the APS Upgrade	96
	J. Wang, G.S. Sprau ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The APS Upgrade of a multi-bend achromat (MBA) storage ring requires a fast bipolar power supply for the fast correction magnets. The key performance requirement of the power supply includes a small-signal bandwidth of 10 kHz for the output current. This requirement presents a challenge to the design because of the high inductance of the magnet load and a limited input DC voltage. A prototype DC/DC power supply utilizing a MOSFET H-bridge circuit with a 500 kHz PWM has been developed and tested successfully. The prototype achieved a 10-kHz bandwidth with less than 3-dB attenuation for a signal 0.5% of the maximum operating current of 15 amperes. This paper presents the design of the power circuit, the PWM method, the control loop, and the test results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB12
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WEPOB05	Operational Experience With Beam Abort System for Superconducting Undulator Quench Mitigation	890
	K.C. Harkay, J.C. Dooling, 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. A beam abort system has been implemented in the Advanced Photon Source storage ring. The abort system works in tandem with the existing machine protection system (MPS), and its purpose is to control the beam loss location and, thereby, minimize beam loss-induced quenches at the two superconducting undulators (SCUs). The abort system consists of a dedicated horizontal kicker designed to kick out all the bunches in a few turns after being triggered by MPS. The abort system concept was developed on the basis of single- and multi-particle tracking simulations using elegant and bench measurements of the kicker pulse. Performance of the abort system–kick amplitudes and loss distributions of all bunches–was analyzed using beam position monitor (BPM) turn histories, and agrees reasonably well with the model. Beam loss locations indicated by the BPMs are consistent with the fast fiber-optic beam loss diagnostics described elsewhere [1]. Operational experience with the abort system, various issues that were encountered, limitations of the system, and quench statistics are described. [1] J. Dooling et al., these proceedings.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB05
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WEPOB24	Preliminary Test Results of a Prototype Fast Kicker for APS MBA Upgrade	950
	C. Yao, A. Barcikowski, A.R. Brill, J. Carwardine, T.K. Clute, Z.A. Conway, A.R. Cours, G. Decker, R.T. Keane, F. Lenkszus, L.H. Morrison, X. Sun, J. Wang, F. Westferro, A. Xiao 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 multi-bend achromatic (MBA) upgrade storage ring plans to support two bunch fill patterns: a 48-bunch and a 324-bunch. A "swap out" injection scheme is required. In order provide the required kick to injected beam, to minimize the beam loss and residual oscillation of injected beam, and to minimize the perturbation to stored beam during injection, the rise, fall, and flat-top parts of the kicker pulse must be within a 16.9-ns interval. Stripling-type kickers are chosen for both injection and extraction. We developed a prototype kicker that supports a ±15kV differential pulse voltage. We performed high voltage discharge, TDR measurement, high voltage pulse test and beam test of the kicker. We report the design of the fast kicker and the test results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB24
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Paper

Title

Page

A High Bandwidth Bipolar Power Supply for the Fast Correctors in the APS Upgrade

96

J. Wang, G.S. Sprau
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The APS Upgrade of a multi-bend achromat (MBA) storage ring requires a fast bipolar power supply for the fast correction magnets. The key performance requirement of the power supply includes a small-signal bandwidth of 10 kHz for the output current. This requirement presents a challenge to the design because of the high inductance of the magnet load and a limited input DC voltage. A prototype DC/DC power supply utilizing a MOSFET H-bridge circuit with a 500 kHz PWM has been developed and tested successfully. The prototype achieved a 10-kHz bandwidth with less than 3-dB attenuation for a signal 0.5% of the maximum operating current of 15 amperes. This paper presents the design of the power circuit, the PWM method, the control loop, and the test results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB12

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WEPOB05

Operational Experience With Beam Abort System for Superconducting Undulator Quench Mitigation

890

K.C. Harkay, J.C. Dooling, 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.
A beam abort system has been implemented in the Advanced Photon Source storage ring. The abort system works in tandem with the existing machine protection system (MPS), and its purpose is to control the beam loss location and, thereby, minimize beam loss-induced quenches at the two superconducting undulators (SCUs). The abort system consists of a dedicated horizontal kicker designed to kick out all the bunches in a few turns after being triggered by MPS. The abort system concept was developed on the basis of single- and multi-particle tracking simulations using elegant and bench measurements of the kicker pulse. Performance of the abort system–kick amplitudes and loss distributions of all bunches–was analyzed using beam position monitor (BPM) turn histories, and agrees reasonably well with the model. Beam loss locations indicated by the BPMs are consistent with the fast fiber-optic beam loss diagnostics described elsewhere [1]. Operational experience with the abort system, various issues that were encountered, limitations of the system, and quench statistics are described.
[1] J. Dooling et al., these proceedings.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB05

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WEPOB24

Preliminary Test Results of a Prototype Fast Kicker for APS MBA Upgrade

950

C. Yao, A. Barcikowski, A.R. Brill, J. Carwardine, T.K. Clute, Z.A. Conway, A.R. Cours, G. Decker, R.T. Keane, F. Lenkszus, L.H. Morrison, X. Sun, J. Wang, F. Westferro, A. Xiao
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 multi-bend achromatic (MBA) upgrade storage ring plans to support two bunch fill patterns: a 48-bunch and a 324-bunch. A "swap out" injection scheme is required. In order provide the required kick to injected beam, to minimize the beam loss and residual oscillation of injected beam, and to minimize the perturbation to stored beam during injection, the rise, fall, and flat-top parts of the kicker pulse must be within a 16.9-ns interval. Stripling-type kickers are chosen for both injection and extraction. We developed a prototype kicker that supports a ±15kV differential pulse voltage. We performed high voltage discharge, TDR measurement, high voltage pulse test and beam test of the kicker. We report the design of the fast kicker and the test results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB24

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