Beam-Foil Lifetime Studies of Highly Ionized Silicon

Abstract

Previous beam-foil lifetime studies in the EUV range are extended to cover all n = 2 states of Si VII and Si IX. The lifetime values obtained agree with theoretical data of Nicolaïdes and Beck. For some states of Si X and Si XI information about initial population ratios of singly and doubly excited states is obtained. After foil excitation, the contribution of cascades from doubly excited states in the n = 2 shell to the intensities of decays from singly excited to ground states amounts to 20-40%.