Compton polarimetry at storage rings

Not scheduled
15m
Rome

Rome

Crowne Plaza Rome - St. Peter's hotel (via Aurelia Antica 415)

Speaker

Wolfgang Hillert (University of Bonn, Physics InstituTe, ELSA)

Description

- functional principle - measurement of the integral asymmetry or the shift of the center of the photon distribution - analyzing power for both methods - achievable resolution, requirements on the detector - photon detection using a counting silicon strip detector - first results

Summary

Using the electron stretcher accelerator ELSA as an example, the method of Compton polarimetry will be explained. It is based on Compton backscattering of circularly polarized laser light off the longitudinally or transversely polarized revolving electrons. Two methods for detecting the backscattered photons will be presented: measurement of the integral asymmetry and measurement of the shift of the center of the photon intensity distribution when changing the helicity of the laser beam. Whereas the analyzing power of the first method is strongly sensitive on width and divergence of the electron beam, the second one is almost independent of the beam parameters. The requirements on the detector, depending on the envisaged measurement precision, will be discussed. A novel method for photon detection, using a counting silicon strip detector, will be presented. First results obtained at ELSA will be presented and compared with a possible employment at future storage rings.

Primary author

Wolfgang Hillert (University of Bonn, Physics InstituTe, ELSA)

Presentation materials