IPAC2015 - List of Authors (Lenkszus, F.)

Paper	Title	Page
MOPWI011	Beam Stability R&D for the APS MBA Upgrade	1167
	N. Sereno, N.D. Arnold, H. Bui, J. Carwardine, G. Decker, L. Emery, R.I. Farnsworth, R.T. Keane, F. Lenkszus, R.M. Lill, R. Lipa, S. Veseli, S. Xu, B.X. Yang ANL, Argonne, Ilinois, USA
	Funding: Results shown in this report result from work performed at Argonne National Laboratory operated by UChicago Argonne, LLC, for the U.S. Department of Energy under contract DE-AC02-06CH11357. Beam diagnostics required for the APS MBA are driven by ambitious beam stability requirements. The major AC stability challenge is to correct rms beam motion to 10% the rms beam size at the insertion device source points from 0.01 to 1000 Hz. The vertical plane represents the biggest challenge for AC stability which is required to be 400 nm rms for a 4 micron vertical beam size. Long term drift over a period of 7 days is required to be 1 micron or less. Major diagnostics R&D components are improved rf beam position processing using commercially available fpga based bpm processors, new XRay beam position monitors sensitive only to hard X-rays, mechanical motion sensing and remediation to detect and correct long term drift and a new feedback system featuring a tenfold increase in sampling rate and a several-fold increase in the number of fast correctors and bpms. Feedback system development represents a major effort and we are pursuing development of a novel algorithm that integrates orbit correction for both slow and fast correctors down to DC simultaneously. Finally a new data acquisition system (DAQ) is being developed to acquire streaming data from all diagnostics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWI011
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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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TUPJE069	Fast Injection System R&D for the APS Upgrade	1797
	F. Lenkszus, J. Carwardine, A.R. Cours, G. Decker, L.H. Morrison, X. Sun, J. Wang, F. Westferro, A. Xiao, C. Yao ANL, Argonne, Ilinois, USA A. Krasnykh SLAC, Menlo Park, California, 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. The MBA upgrade for the APS will operate with bunch swap out and on axis injection. The planned 324 bunch fill pattern places difficult demands on the injection and extraction kickers. The present concept uses dual stripline kickers driven by high Voltage pulsers. Minimizing perturbation on adjacent bunches requires very fast rise and fall times with relatively narrow ~20 nsec, 15 kV pulses. To achieve these requirements we have initiated a multifaceted R&D program. The R&D includes the HV pulser, stripline kicker and HV feedthrough. We have purchased a commercial dual channel HV pulser and are evaluating its performance and reliability. In addition, we are investigating the feasibility of using nonlinear ferrite loaded coaxial cables (shockwave transmission line) to sharpen the leading and trailing edges of high voltage pulses. We are also developing a prototype kicker and high voltage feedthrough. The requirements for injection and extraction, progress on prototype development and results of our HV pulser investigations will be reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE069
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WEPTY014	Development of Fast Kickers for the APS MBA Upgrade	3286
	C. Yao, J. Carwardine, A.R. Cours, F. Lenkszus, R.R. Lindberg, L.H. Morrison, X. Sun, J. Wang, F. Westferro, A. Xiao ANL, Argonne, Ilinois, USA
	Funding: *Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The APS multi-bend achromat (MBA) upgrade storage ring will support two bunch fill patterns: a 48-singlets and a 324-singlets. A “swap out” injection scheme is adopted. In order to minimize the beam loss and residual oscillation of injected beam and to minimize the perturbation of stored beam during a swap-on injection, the rise, fall, and flat-top parts of the kicker pulse must be held within a 22.8-ns interval. Traditional ferrite-core-type kickers can’t meet the timing requirements; therefore, we decided to use stripline-type kickers. We have completed a preliminary design of a prototype kicker geometry. Procurement of the pulser supply and other components of an evaluation system is under way. We report the specification and design of the fast kicker and current status.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY014
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Paper

Title

Page

Beam Stability R&D for the APS MBA Upgrade

1167

N. Sereno, N.D. Arnold, H. Bui, J. Carwardine, G. Decker, L. Emery, R.I. Farnsworth, R.T. Keane, F. Lenkszus, R.M. Lill, R. Lipa, S. Veseli, S. Xu, B.X. Yang
ANL, Argonne, Ilinois, USA

Funding: Results shown in this report result from work performed at Argonne National Laboratory operated by UChicago Argonne, LLC, for the U.S. Department of Energy under contract DE-AC02-06CH11357.
Beam diagnostics required for the APS MBA are driven by ambitious beam stability requirements. The major AC stability challenge is to correct rms beam motion to 10% the rms beam size at the insertion device source points from 0.01 to 1000 Hz. The vertical plane represents the biggest challenge for AC stability which is required to be 400 nm rms for a 4 micron vertical beam size. Long term drift over a period of 7 days is required to be 1 micron or less. Major diagnostics R&D components are improved rf beam position processing using commercially available fpga based bpm processors, new XRay beam position monitors sensitive only to hard X-rays, mechanical motion sensing and remediation to detect and correct long term drift and a new feedback system featuring a tenfold increase in sampling rate and a several-fold increase in the number of fast correctors and bpms. Feedback system development represents a major effort and we are pursuing development of a novel algorithm that integrates orbit correction for both slow and fast correctors down to DC simultaneously. Finally a new data acquisition system (DAQ) is being developed to acquire streaming data from all diagnostics.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWI011

Export •

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

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

Export •

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

TUPJE069

Fast Injection System R&D for the APS Upgrade

1797

F. Lenkszus, J. Carwardine, A.R. Cours, G. Decker, L.H. Morrison, X. Sun, J. Wang, F. Westferro, A. Xiao, C. Yao
ANL, Argonne, Ilinois, USA
A. Krasnykh
SLAC, Menlo Park, California, 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.
The MBA upgrade for the APS will operate with bunch swap out and on axis injection. The planned 324 bunch fill pattern places difficult demands on the injection and extraction kickers. The present concept uses dual stripline kickers driven by high Voltage pulsers. Minimizing perturbation on adjacent bunches requires very fast rise and fall times with relatively narrow ~20 nsec, 15 kV pulses. To achieve these requirements we have initiated a multifaceted R&D program. The R&D includes the HV pulser, stripline kicker and HV feedthrough. We have purchased a commercial dual channel HV pulser and are evaluating its performance and reliability. In addition, we are investigating the feasibility of using nonlinear ferrite loaded coaxial cables (shockwave transmission line) to sharpen the leading and trailing edges of high voltage pulses. We are also developing a prototype kicker and high voltage feedthrough. The requirements for injection and extraction, progress on prototype development and results of our HV pulser investigations will be reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE069

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

WEPTY014

Development of Fast Kickers for the APS MBA Upgrade

3286

C. Yao, J. Carwardine, A.R. Cours, F. Lenkszus, R.R. Lindberg, L.H. Morrison, X. Sun, J. Wang, F. Westferro, A. Xiao
ANL, Argonne, Ilinois, USA

Funding: *Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The APS multi-bend achromat (MBA) upgrade storage ring will support two bunch fill patterns: a 48-singlets and a 324-singlets. A “swap out” injection scheme is adopted. In order to minimize the beam loss and residual oscillation of injected beam and to minimize the perturbation of stored beam during a swap-on injection, the rise, fall, and flat-top parts of the kicker pulse must be held within a 22.8-ns interval. Traditional ferrite-core-type kickers can’t meet the timing requirements; therefore, we decided to use stripline-type kickers. We have completed a preliminary design of a prototype kicker geometry. Procurement of the pulser supply and other components of an evaluation system is under way. We report the specification and design of the fast kicker and current status.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY014

Export •

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