Production of Autoionizing Di-excited States of Barium with High Angular Momentum

Autoionizing di-excited states Ba(6 p 1/2 27 l ) with 7 ⩽ l ⩽ 26, have been experimentally detected. They have been produced by a method combining excitation by two lasers and l -mixing collisions between barium and xenon. Results show that a long delay between the two laser excitation steps is favourable to the production of these states. The method has proved to be very efficient (measured cross-section: σ = 3.1 · 10 -13 cm 2 ) for populating high-angular-momentum autoionizing states of barium.