IPAC2016 - List of Authors (Switka, M.T.)

Paper	Title	Page
MOPMB010	Compton Polarimetry at ELSA - Beamline and Detector Optimization	95
	R. Koop, W. Hillert, M.T. Switka ELSA, Bonn, Germany
	Funding: Work supported by DFG within CRC TRR16 The Electron Stretcher Facility ELSA provides a polarized electron beam with energies of 0.5 - 3.2 GeV for double polarization hadron physics experiments. Monitoring the vertical electron polarization by Compton polarimetry in the stretcher ring has several advantages over the established polarization measurement by Moeller polarimetry. The Compton polarimeter setup presented consists of a 40 W cw disk laser featuring two polarized photon beams colliding head-on with the stored electron beam in ELSA. A silicon strip detector measures the vertical intensity profile of the backscattered photons. The reversal of handedness of the laser beam's circular polarization results in a polarization dependent vertical shift of this profile. From a calibration using time dependent polarization build-up due to the Sokolov-Ternov effect, the polarization degree of the electron beam can be extracted. After recent laser repairs as well as beamline and detector modifications, first measurement attempts of the electron's polarization degree were conducted. The performance of the beamline and first measurements are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB010
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THPOW029	Single Electron Extraction at the ELSA Detector Test Beamline	4002
	F. Frommberger, N. Heurich, W. Hillert, T. Schiffer, M.T. Switka ELSA, Bonn, Germany
	The Electron pulse Stretcher Facility ELSA delivers polarized and non-polarized electrons with an adjustable beam energy of 0.5 - 3.2 GeV to external experimental stations. Extraction currents available range down from 1 nanoampere to several atto-amperes provided by single electron extraction. Especially the high energy physics community requires detector test stations with electron tagging rates between 100 Hz to 100 kHz, imposing particular requirements for stable minimum-current extraction from the storage ring. These requirements are met with the implementation of a low-injection mode for the booster synchrotron and photomultiplier-based stored current monitoring, providing feedback for a selectable limit of the injected current. A homogeneous extraction current with duty factor > 80% is routinely granted by the excitation of a 3rd integer optical resonance. The setup of the low-current injection system and measurements of the extraction properties at the preliminary detector test beamline are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW029
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Compton Polarimetry at ELSA - Beamline and Detector Optimization

95

R. Koop, W. Hillert, M.T. Switka
ELSA, Bonn, Germany

Funding: Work supported by DFG within CRC TRR16
The Electron Stretcher Facility ELSA provides a polarized electron beam with energies of 0.5 - 3.2 GeV for double polarization hadron physics experiments. Monitoring the vertical electron polarization by Compton polarimetry in the stretcher ring has several advantages over the established polarization measurement by Moeller polarimetry. The Compton polarimeter setup presented consists of a 40 W cw disk laser featuring two polarized photon beams colliding head-on with the stored electron beam in ELSA. A silicon strip detector measures the vertical intensity profile of the backscattered photons. The reversal of handedness of the laser beam's circular polarization results in a polarization dependent vertical shift of this profile. From a calibration using time dependent polarization build-up due to the Sokolov-Ternov effect, the polarization degree of the electron beam can be extracted. After recent laser repairs as well as beamline and detector modifications, first measurement attempts of the electron's polarization degree were conducted. The performance of the beamline and first measurements are presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB010

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

THPOW029

Single Electron Extraction at the ELSA Detector Test Beamline

4002

F. Frommberger, N. Heurich, W. Hillert, T. Schiffer, M.T. Switka
ELSA, Bonn, Germany

The Electron pulse Stretcher Facility ELSA delivers polarized and non-polarized electrons with an adjustable beam energy of 0.5 - 3.2 GeV to external experimental stations. Extraction currents available range down from 1 nanoampere to several atto-amperes provided by single electron extraction. Especially the high energy physics community requires detector test stations with electron tagging rates between 100 Hz to 100 kHz, imposing particular requirements for stable minimum-current extraction from the storage ring. These requirements are met with the implementation of a low-injection mode for the booster synchrotron and photomultiplier-based stored current monitoring, providing feedback for a selectable limit of the injected current. A homogeneous extraction current with duty factor > 80% is routinely granted by the excitation of a 3rd integer optical resonance. The setup of the low-current injection system and measurements of the extraction properties at the preliminary detector test beamline are presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW029

Export •

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