Bound-state transitions in few-electron, heavy ions following radiative electron capture are studied within the framework of the density matrix theory and the multiconfiguration Dirac-Fock approach. Special attention is paid to the K α1 (1 s1/2 2 p3/2 P J=1,2 1,3 →1 s 1/2 2 S J=0 1) radiative decay of heliumlike uranium U90+ projectiles. This decay has recently been observed at the GSI facility in Darmstadt, giving rise to a surprisingly isotropic angular distribution, which is inconsistent with previous experiments and calculations based on a "one-particle" model. We show that the unexpected isotropy essentially results from the mutual cancellation of the angular distributions of the P11 → S01 electric dipole and P23 → S01 magnetic quadrupole transitions, both of which contribute to the K α1 radiation. Detailed computations on the anisotropy of the K α1 radiation have been carried out for a wide range of projectile energies and are compared to available experimental data.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - Nov 23 2006|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics