IPAC2014 - List of Authors (Switka, M.T.)

Paper	Title	Page
TUPRI016	First Studies on Ion Effects in the Accelerator ELSA	1585
	D. Sauerland, W. Hillert, M.T. Switka ELSA, Bonn, Germany A. Markoviḱ, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany A. Meseck HZB, Berlin, Germany
	Funding: BMBF (Federal Ministry of Education and Research) In the ELSA stretcher ring electrons are accelerated by a fast energy ramp of 6 GeV/s to a beam energy of 3.2 GeV. The high energetic electrons ionize the residual gas molecules in the beam pipe by collisions or synchrotron radiation. The generated ions in turn accumulate inside the beam potential, causing several undesired effects such as tune shifts and beam instabilities. These effects are studied experimentally at ELSA using its full diagnostic capabilities. Both tune shifts due to beam neutralization and transversal beam-ion instabilities can be determined from the beam spectrum. Additionally the beam's transfer function can be measured using a broadband transversal kicker. In the stretcher ring at a beam energy of 1.2 GeV, a periodic beam blow-up was detected in the horizontal plane. Additional measurements of the transversal beam spectrum and ns-time resolution observations with a streak camera identified this blow-up as a coherent dipole oscillation of the beam. This horizontal instability is presumably caused by trapped ions, as there is a strong correlation with the high voltage-bias of the clearing electrodes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI016
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THPME098	Set up of a Synchrotron Light Monitor at the 2.5 GeV Booster Synchrotron at ELSA	3468
	T. Schiffer Uni Bonn, Bonn, Germany P. Hänisch, W. Hillert, M.T. Switka ELSA, Bonn, Germany
	For the upgrade of the accelerator facility ELSA towards higher stored beam currents, a non-destructive beam analysis is being implemented at the 2.5 GeV booster synchrotron. It is a fast ramping combined function synchrotron with an extraction repetition rate of 50 Hz. Typically, beam currents of 10 mA are accelerated from 20 MeV to the extraction energy of 1.2 GeV within 8.6 ms, hence the magnetic field is increased by up to 85 T/s. A synchrotron light monitor as the primary diagnostic tool will be utilized for measuring the transversal position and intensity distribution of the beam. Its dynamics on the fast energy ramp is of distinct interest. The proposed set-up of the synchrotron light monitor and the current development are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME098
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THPME099	Synchrotron Radiation Diagnostics Performance at ELSA	3471
	M.T. Switka, F. Frommberger, P. Hänisch, W. Hillert, D. Proft, M. Schedler, S. Zander ELSA, Bonn, Germany
	Funding: Work funded by the DFG within SFB/TRR16. The pulse stretcher ring ELSA delivers polarized and non-polarized electrons with an adjustable beam energy of 0.5 - 3.5 GeV to external experimental stations. To meet the growing demands of the user community regarding beam intensity and quality, the upgrade of vital accelerator components is an ongoing process. This includes the improvement of the beam diagnostics in order to resolve and monitor intensity and quality limiting effects. ELSA has recently been equipped with a diagnostic synchrotron radiation beamline housing a streak camera as main beam imaging device. It extends the diagnostics capabilities into the picosecond temporal resolution regime and captures fast longitudinal and transverse beam dynamics. The obtained measurements provide crucial feedback for further machine optimization. The overall performance of the streak camera system and machine relevant measurements are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME099
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Paper

Title

Page

First Studies on Ion Effects in the Accelerator ELSA

1585

D. Sauerland, W. Hillert, M.T. Switka
ELSA, Bonn, Germany
A. Markoviḱ, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
A. Meseck
HZB, Berlin, Germany

Funding: BMBF (Federal Ministry of Education and Research)
In the ELSA stretcher ring electrons are accelerated by a fast energy ramp of 6 GeV/s to a beam energy of 3.2 GeV. The high energetic electrons ionize the residual gas molecules in the beam pipe by collisions or synchrotron radiation. The generated ions in turn accumulate inside the beam potential, causing several undesired effects such as tune shifts and beam instabilities. These effects are studied experimentally at ELSA using its full diagnostic capabilities. Both tune shifts due to beam neutralization and transversal beam-ion instabilities can be determined from the beam spectrum. Additionally the beam's transfer function can be measured using a broadband transversal kicker. In the stretcher ring at a beam energy of 1.2 GeV, a periodic beam blow-up was detected in the horizontal plane. Additional measurements of the transversal beam spectrum and ns-time resolution observations with a streak camera identified this blow-up as a coherent dipole oscillation of the beam. This horizontal instability is presumably caused by trapped ions, as there is a strong correlation with the high voltage-bias of the clearing electrodes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI016

Export •

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

THPME098

Set up of a Synchrotron Light Monitor at the 2.5 GeV Booster Synchrotron at ELSA

3468

T. Schiffer
Uni Bonn, Bonn, Germany
P. Hänisch, W. Hillert, M.T. Switka
ELSA, Bonn, Germany

For the upgrade of the accelerator facility ELSA towards higher stored beam currents, a non-destructive beam analysis is being implemented at the 2.5 GeV booster synchrotron. It is a fast ramping combined function synchrotron with an extraction repetition rate of 50 Hz. Typically, beam currents of 10 mA are accelerated from 20 MeV to the extraction energy of 1.2 GeV within 8.6 ms, hence the magnetic field is increased by up to 85 T/s. A synchrotron light monitor as the primary diagnostic tool will be utilized for measuring the transversal position and intensity distribution of the beam. Its dynamics on the fast energy ramp is of distinct interest. The proposed set-up of the synchrotron light monitor and the current development are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME098

Export •

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

THPME099

Synchrotron Radiation Diagnostics Performance at ELSA

3471

M.T. Switka, F. Frommberger, P. Hänisch, W. Hillert, D. Proft, M. Schedler, S. Zander
ELSA, Bonn, Germany

Funding: Work funded by the DFG within SFB/TRR16.
The pulse stretcher ring ELSA delivers polarized and non-polarized electrons with an adjustable beam energy of 0.5 - 3.5 GeV to external experimental stations. To meet the growing demands of the user community regarding beam intensity and quality, the upgrade of vital accelerator components is an ongoing process. This includes the improvement of the beam diagnostics in order to resolve and monitor intensity and quality limiting effects. ELSA has recently been equipped with a diagnostic synchrotron radiation beamline housing a streak camera as main beam imaging device. It extends the diagnostics capabilities into the picosecond temporal resolution regime and captures fast longitudinal and transverse beam dynamics. The obtained measurements provide crucial feedback for further machine optimization. The overall performance of the streak camera system and machine relevant measurements are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME099

Export •

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