C. Shah,
H. Jörg,
S. Bernitt,
S. Dobrodey,
R. Steinbrügge,
C. Beilmann,
P. Amaro,
Z. Hu,
S. Weber,
S. Fritzsche,
A. Surzhykov,
J. Crespo López-Urrutia,
and S. Tashenov
Polarization measurement of dielectronic recombination transitions in highly charged krypton ions
Phys. Rev. A, 92 :042702 (October 2015)
Polarization measurement of dielectronic recombination transitions in highly charged krypton ions
Phys. Rev. A, 92 :042702 (October 2015)
Abstract:
We report linear polarization measurements of x rays emitted due to dielectronic recombination into highly charged krypton ions. The ions in the He-like through O-like charge states were populated in an electron-beam ion trap with the electron-beam energy adjusted to recombination resonances in order to produce Ka x rays. The x rays were detected with a newly developed Compton polarimeter using a beryllium scattering target and 12 silicon x-ray detector diodes sampling the azimuthal distribution of the scattered x rays. The extracted degrees of linear polarization of several dielectronic recombination transitions agree with results of relativistic distorted-wave calculations. We also demonstrate a high sensitivity of the polarization to the Breit interaction, which is remarkable for a medium-Z element like krypton. The experimental results can be used for polarization diagnostics of hot astrophysical and laboratory fusion plasmas.