Negative-ion resonances and cusps in4 1,3Pelectron excitation functions of the zinc atom

Abstract

Negative-ion resonance structures, cusps, and possibly broad shape resonances were observed in the electron impact excitation of the $4s4p {}^{1}{P}_{1}$ and $4s4p {}^{3}{P}_{0,1,2}$ states of zinc near the thresholds of the lowest autoionizing states. Angle differential scattered electron excitation functions show strong contributions from the decay of negative-ion resonances built on a $3d$ excited ion core with final state spin-dependent decay. Most resonances have a $3{d}^{9}{\mathit{ns}}^{2}4{p}^{2}$ electron configuration, and they appear in one or both of the ${}^{1}{P}_{1}$ and ${}^{3}{P}_{0,1,2}$ states but with different branching ratios and angular behaviors.