IBIC2018 - List of Authors (Schiwietz, G.)

Paper	Title	Page
TUPB04	Development of a New Button Beam-position Monitor for BESSY VSR	265
	J.G. Hwang, V. Dürr, M. Ries, A. Schälicke, G. Schiwietz, D. Wolk HZB, Berlin, Germany
	An extreme operation mode such as the BESSY-VSR conditions stimulates the development of a high accuracy bunch-by-bunch beam-position monitor (BPM) system which is compatible with the bunch-selective operation for the orbit feedback system. Such a system will also greatly benefit to accelerator R&D such as transverse resonance island buckets (TRIBs). Compensation of the long-range ringing signal produced by the combined effect of impedance mismatching inside the button and trapped TE-modes in the aluminum-oxide insulator (Al2O3) material is required essentially to improve the resolution. This is important since the ringing causes a misreading of the beam position and current of following bunches. We show the design study of a new button-type BPM to mitigate the influence of the ringing signal as well as to reduce wake losses by improving the impedance matching in the button and by replacing the insulator material.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUPB04
About •	paper received ※ 04 September 2018 paper accepted ※ 11 September 2018 issue date ※ 29 January 2019
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WEPA02	Recent Progress of Bunch Resolved Beam Diagnostics for BESSY VSR	379
	J.G. Hwang, T. Atkinson, P. Goslawski, A. Jankowiak, M. Koopmans, T. Mertens, M. Ries, A. Schälicke, G. Schiwietz HZB, Berlin, Germany
	BESSY VSR is an upgrade project of the existing storage ring BESSY II to create long and short photon pulses simultaneously for all beam lines by installing additional superconducting cavities with harmonic frequencies of 1.5 GHz and 1.75 GHz. The storage-ring operation will be influenced by a transient beam-loading effect of all cavities and by the complex filling pattern due to the disparity in the current of long and short bunches. This, in turn, could introduce a variation of beam trajectory, transverse profile, and length for the different bunches. This stimulates the development of bunch-resolved monitors for bunch length, beam size, filling pattern and beam trajectory displacement. In this paper, we show new developments of crucial beam diagnostics including measurements of the bunch-resolved temporal profile with a resolution of less than 1 ps FWHM and bunch-resolved profile with a resolution of less than 10 um rms. The upgrade of the booster beam-diagnostics will be discussed as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPA02
About •	paper received ※ 04 September 2018 paper accepted ※ 13 September 2018 issue date ※ 29 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Development of a New Button Beam-position Monitor for BESSY VSR

265

J.G. Hwang, V. Dürr, M. Ries, A. Schälicke, G. Schiwietz, D. Wolk
HZB, Berlin, Germany

An extreme operation mode such as the BESSY-VSR conditions stimulates the development of a high accuracy bunch-by-bunch beam-position monitor (BPM) system which is compatible with the bunch-selective operation for the orbit feedback system. Such a system will also greatly benefit to accelerator R&D such as transverse resonance island buckets (TRIBs). Compensation of the long-range ringing signal produced by the combined effect of impedance mismatching inside the button and trapped TE-modes in the aluminum-oxide insulator (Al2O3) material is required essentially to improve the resolution. This is important since the ringing causes a misreading of the beam position and current of following bunches. We show the design study of a new button-type BPM to mitigate the influence of the ringing signal as well as to reduce wake losses by improving the impedance matching in the button and by replacing the insulator material.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUPB04

About •

paper received ※ 04 September 2018 paper accepted ※ 11 September 2018 issue date ※ 29 January 2019

Export •

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

WEPA02

Recent Progress of Bunch Resolved Beam Diagnostics for BESSY VSR

379

J.G. Hwang, T. Atkinson, P. Goslawski, A. Jankowiak, M. Koopmans, T. Mertens, M. Ries, A. Schälicke, G. Schiwietz
HZB, Berlin, Germany

BESSY VSR is an upgrade project of the existing storage ring BESSY II to create long and short photon pulses simultaneously for all beam lines by installing additional superconducting cavities with harmonic frequencies of 1.5 GHz and 1.75 GHz. The storage-ring operation will be influenced by a transient beam-loading effect of all cavities and by the complex filling pattern due to the disparity in the current of long and short bunches. This, in turn, could introduce a variation of beam trajectory, transverse profile, and length for the different bunches. This stimulates the development of bunch-resolved monitors for bunch length, beam size, filling pattern and beam trajectory displacement. In this paper, we show new developments of crucial beam diagnostics including measurements of the bunch-resolved temporal profile with a resolution of less than 1 ps FWHM and bunch-resolved profile with a resolution of less than 10 um rms. The upgrade of the booster beam-diagnostics will be discussed as well.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPA02

About •

paper received ※ 04 September 2018 paper accepted ※ 13 September 2018 issue date ※ 29 January 2019

Export •

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