Population of the Three Major Exit Channels in the 3d Resonance Region of Atomic Gallium

The exit channels in the region of the 3d→4p resonance of atomic gallium were determined in a photoemission experiment. The population of the three major channels involving $4p$ and $4s$ electrons was measured by the constant-ionic-state method for twenty resonant states between 18.8 and 21.7 eV, and the angular distribution of the emitted electrons was obtained. As a result, an autoionization case in which many resonances and many continua are coupled has been characterized in the most comprehensive experiment to date.