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 1.3PJ=1,2→1s21/2 1SJ=0) 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 1P1 → 1S0 electric dipole and 3P2 → 1S0 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.
A. S. Surzhykov et al., "K α1 Radiation from Heavy, Heliumlike Ions Produced in Relativistic Collisions," Physical Review A - Atomic, Molecular, and Optical Physics, vol. 74, no. 5, pp. 052710-1-052710-5, American Physical Society (APS), Nov 2006.
The definitive version is available at https://doi.org/10.1103/PhysRevA.74.052710
Keywords and Phrases
Anisotropy; Computation Theory; Electrons; Magnetic Properties; Uranium; Heliumlike Ions; Isotropic Angular Distribution; Isotropy; Relativistic Collisions; Heavy Ions
International Standard Serial Number (ISSN)
Article - Journal
© 2006 American Physical Society (APS), All rights reserved.