IPAC2015 - List of Authors (Yang, B.X.)

Paper	Title	Page
MOPMA013	Experience with Round Beam Operation at the Advanced Photon Source	562
	A. Xiao, L. Emery, V. Sajaev, B.X. Yang ANL, Argonne, Ilinois, 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 Very short Touschek lifetime becomes a common issue for next-generation ultra-low emittance storage ring light sources. In order to reach a longer beam lifetime, such a machine often requires operating with a vertical-to-horizontal emittance ratio close to an unity, i.e. a ‘‘round beam''. In tests at the APS storage ring, we determined how a round beam can be reached experimentally. Some general issues, such as beam injection, optics measurement and corrections, and orbit correction have been tested also. To demonstrate that a round beam was achieved, the beam size ratio is calibrated using beam lifetime measurement.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMA013
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MOPWI010	Design and Development of a Beam Stablity Mechanical Motion System Diagnostic for the APS MBA Upgrade	1164
	R.M. Lill, G. Decker, N. Sereno, 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. The Advanced Photon Source (APS) is currently in the conceptual design phase for the MBA lattice upgrade. In order to achieve long-term beam stability goals, a Mechanical Motion System (MMS) has been designed to monitor critical in-tunnel beam position monitoring devices. The mechanical motion generated from changes in chamber cooling water temperature, tunnel air temperature, beam current and undulator gap positon causes erroneous changes in beam position measurements causing drift in the X-ray beam position. The MMS has been prototyped and presently provides critical information on the vacuum chamber and BPM support systems. We report on first results of the prototype system installed in the APS storage ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWI010
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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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MOPWI014	Design and Development for the Next Generation X-ray Beam Position Monitor System at the APS	1175
	B.X. Yang, G. Decker, Y. Jaski, S.-H. Lee, M. Ramanathan, N. Sereno, F. Westferro ANL, Argonne, Ilinois, USA
	Funding: Work performed at Argonne National Laboratory, operated by UChicago Argonne, LLC, for the U.S. Department of Energy under contract DE-AC02-06CH11357. The proposed Advanced Photon Source (APS) Upgrade will bring storage-ring beam sizes down to several micrometers and require x-ray beam directional stability in 100 nrad range for undulator power exceeding 16 kW. The next generation x-ray beam position monitors (XBPMs) are designed to meet these requirements. We present first commissioning data on the recently installed grazing-incidence insertion device x-ray beam position monitor (GRID-XBPM) based on Cu K-edge x-ray fluorescence from limiting absorbers of the front end for two inline undulators. It demonstrated a 50-fold improvement for signal-to-background ratio over existing photoemission-based XBPMs. Techniques for calibrating the XBPMs will be discussed. We will also present a new XBPM design based Compton scattering from diamond blades. This XBPM is designed for less powerful undulators such as the APS canted-undulator beamlines where each undulator generates < 10 kW of beam power. We will discuss the thermal design of the blade, the optics design of the detector assembly, and computer simulations of expected response to the x-ray beam. Test data of the prototype may be presented if available.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWI014
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Paper

Title

Page

Experience with Round Beam Operation at the Advanced Photon Source

562

A. Xiao, L. Emery, V. Sajaev, B.X. Yang
ANL, Argonne, Ilinois, 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
Very short Touschek lifetime becomes a common issue for next-generation ultra-low emittance storage ring light sources. In order to reach a longer beam lifetime, such a machine often requires operating with a vertical-to-horizontal emittance ratio close to an unity, i.e. a ‘‘round beam''. In tests at the APS storage ring, we determined how a round beam can be reached experimentally. Some general issues, such as beam injection, optics measurement and corrections, and orbit correction have been tested also. To demonstrate that a round beam was achieved, the beam size ratio is calibrated using beam lifetime measurement.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMA013

Export •

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

MOPWI010

Design and Development of a Beam Stablity Mechanical Motion System Diagnostic for the APS MBA Upgrade

1164

R.M. Lill, G. Decker, N. Sereno, 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.
The Advanced Photon Source (APS) is currently in the conceptual design phase for the MBA lattice upgrade. In order to achieve long-term beam stability goals, a Mechanical Motion System (MMS) has been designed to monitor critical in-tunnel beam position monitoring devices. The mechanical motion generated from changes in chamber cooling water temperature, tunnel air temperature, beam current and undulator gap positon causes erroneous changes in beam position measurements causing drift in the X-ray beam position. The MMS has been prototyped and presently provides critical information on the vacuum chamber and BPM support systems. We report on first results of the prototype system installed in the APS storage ring.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWI010

Export •

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

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

MOPWI014

Design and Development for the Next Generation X-ray Beam Position Monitor System at the APS

1175

B.X. Yang, G. Decker, Y. Jaski, S.-H. Lee, M. Ramanathan, N. Sereno, F. Westferro
ANL, Argonne, Ilinois, USA

Funding: Work performed at Argonne National Laboratory, operated by UChicago Argonne, LLC, for the U.S. Department of Energy under contract DE-AC02-06CH11357.
The proposed Advanced Photon Source (APS) Upgrade will bring storage-ring beam sizes down to several micrometers and require x-ray beam directional stability in 100 nrad range for undulator power exceeding 16 kW. The next generation x-ray beam position monitors (XBPMs) are designed to meet these requirements. We present first commissioning data on the recently installed grazing-incidence insertion device x-ray beam position monitor (GRID-XBPM) based on Cu K-edge x-ray fluorescence from limiting absorbers of the front end for two inline undulators. It demonstrated a 50-fold improvement for signal-to-background ratio over existing photoemission-based XBPMs. Techniques for calibrating the XBPMs will be discussed. We will also present a new XBPM design based Compton scattering from diamond blades. This XBPM is designed for less powerful undulators such as the APS canted-undulator beamlines where each undulator generates < 10 kW of beam power. We will discuss the thermal design of the blade, the optics design of the detector assembly, and computer simulations of expected response to the x-ray beam. Test data of the prototype may be presented if available.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWI014

Export •

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