Very recently, at the jet-target of the storage ring ESR, a very first polarization study for REC into the K-shell has been performed for bare uranium ions (400 MeV/u). For this purpose a 4x4 planar germanium pixel detector with a pixel size of 7x7 mm has been used, mounted at an observation angle of 90^o. In the experiment the photon polarization can be derived from a coincident registration of events (Compton scattering) occurring simultaneously in two pixels. An accurate value for the linear degree of polarization can be obtained by analyzing all the different combinations of pixel pairs with respect to the angle theta, where theta is the angle between the polarization vector of the initial photon and the propagation direction of the scattered one. We can already state that the K-REC radiation is strongly polarized within the scattering plane (for unpolarized target electrons and projectiles polarization can take place only within or perpendicular to the scattering plane).

References:

A. Surzhykov, S. Fritzsche, Th. Stöhlker, Phys. Lett. A 289, (2001) 213 (Phys. Lett. link)
J. Eichler and A. Ichihara, Phys. Rev. A 65, (2002) 062716
S. Tachenov, Th. Stöhlker et al., GSI Scientific Report 2002 (PS version)
A. Surzhykov, S. Fritzsche et al., GSI Scientific Report 2002 (PDF version)
Th. Stöhlker et al., Nuclear Instruments and Methods in Physics Research B 205 (2003) 210–214 (NIMB link)

Talks and posters:

Poster - Applications of Position Sensitive Germanium Detectors for X-Ray Spectroscopy of Highly-Charged Heavy Ions. (PDF version)
Poster - Polarization studies for radiative recombination transitions into High-Z ions (PDF version)
Talk ( S. Tachenov) - Photon polarization for electron capture in relativistic ion-atom collisions (PDF version)

Links:

Polarization studies (Research part of this page)

Photos: