L -Subshell Resolved Photon Angular Distribution of Radiative Electron Capture into He-like Uranium

The photon angular distributions for radiative electron capture (REC) into the j=1/2 and j=3/2 L subshell levels were measured and calculated for U⁹⁰⁺ {→} C collisions at 89 MeV/u. The experiment provides the first study of the photon angular distribution of REC into a projectile p state (j=3/2) which was found to exhibit a slight backward peaking in the laboratory frame. For radiative capture to the j=1/2 states, the measured angular distribution deviates considerably from symmetry around 90^∘{}. The results demonstrate that the usual sin²θlab distribution is not valid in the high-Z regime.