Energy-pooling ionization via an autoionizing state in indium

Energy-transfer collisions between two 6 ${}_{}{}^2{}_{}{}^{}$ ${\mathit{S}}_{1/2}$ laser-excited indium atoms leading either to ionization of one of the colliding atoms or to population of its ${\mathit{n}}^2$P Rydberg states, have been studied. Atomic lines corresponding to the 5s5${\mathit{p}}^2$ ${}_{}{}^2{}_{}{}^{}$D→5${\mathit{s}}^2$6p ${}_{}{}^2{}_{}{}^{}$ ${\mathit{P}}_{1/2,3/2}$ interconfiguration transitions have been recorded as evidence of the energy-pooling ionization via an autoionizing state. Atomic lines corresponding to the ${\mathit{n}}^2$P→6 ${}_{}{}^2{}_{}{}^{}$S transitions for n=9, 10, and 11 as well as to the 5 ${}_{}{}^2{}_{}{}^{}$D→5 ${}_{}{}^2{}_{}{}^{}$P transitions have proven that the population of highly excited indium atomic states is through the energy-poolimg collisions.