IBIC2016 - List of Authors (Vargas, J.L.)

Paper	Title	Page
MOPG03	Investigation of Transverse Beam Instability Induced by an In-vacuum Undulator at SPEAR3	31
	K. Tian, J.J. Sebek, J.L. Vargas SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy Contract No. DE-AC02-76SF00515 Vertical beam instabilities have been observed at SPEAR3 when a newly installed in-vacuum undulator (IVUN) is operated at a set of narrow gap settings. The source of the instabilities is believed to be vertically deflecting trapped modes inside the IVUN tank that are excited by the beam. We have used beam-based measurements to characterize the frequencies and strengths of the excited modes using both our bunch-by-bunch feedback system and a spectrum analyzer. Using numerical simulations of our IVUN structure, we have found modes with high shunt impedance near the measured frequencies. Recently, we have successfully measured these IVUN modes during our current downtime. In this paper, we will report on the measurements, simulations, and plans to damp these modes.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG03
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Paper

Title

Page

Investigation of Transverse Beam Instability Induced by an In-vacuum Undulator at SPEAR3

31

K. Tian, J.J. Sebek, J.L. Vargas
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy Contract No. DE-AC02-76SF00515
Vertical beam instabilities have been observed at SPEAR3 when a newly installed in-vacuum undulator (IVUN) is operated at a set of narrow gap settings. The source of the instabilities is believed to be vertically deflecting trapped modes inside the IVUN tank that are excited by the beam. We have used beam-based measurements to characterize the frequencies and strengths of the excited modes using both our bunch-by-bunch feedback system and a spectrum analyzer. Using numerical simulations of our IVUN structure, we have found modes with high shunt impedance near the measured frequencies. Recently, we have successfully measured these IVUN modes during our current downtime. In this paper, we will report on the measurements, simulations, and plans to damp these modes.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG03

Export •

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