Polarization of M2 Line Emitted Following Electron-Impact Excitation of Beryllium-Like Ions
SHI Ying-Long1,2, DONG Chen-Zhong1**, MA Xiao-Yun1, WU Zhong-Wen1, XIE Lu-You1, FRITZSCHE Stephan3
1Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 2College of Physics and Information Science, Tianshui Normal University, Tianshui 741001 3Helmholtz-Institut Jena, Fr?belstieg 3, Jena D-07743, Germany and Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universit?t Jena, Max-Wien-Platz 1, Jena D-07743, Germany
Abstract：Detailed calculations are carried out for the electron-impact excitation cross sections from the ground state to the individual magnetic sublevels of the 1s2s22p3/2 J=2 excited state of highly-charged beryllium-like ions by using a fully relativistic distorted-wave (RDW) method. The contributions of the Breit interaction to the linear polarization of the 1s2s22p3/2 J=2→1s22s2 J=0 magnetic quadrupole (M2) line are investigated systematically for the beryllium isoelectronic sequence with 42≤Z ≤92. It is found that the Breit interaction depolarizes significantly the linear polarization of the M2 fluorescence radiation and that these depolarization effects increase as the incident electron energy and/or the atomic number is enlarged.
2013, Vol. 30 
