The Anion Photoelectron Spectrometer Used in Studying Binary Metal Anion Cluster

A home-made magnetic-bottle time-of-flight anion photoelectron spectrometer（PES）for the investigation of binary metal cluster geometry and electron structure is described. The photoelectron spectrometer is installed near the first space focus of home-made reflectron time of flight mass spectrometer（RTOFMS），coupled with laser ablation，pulse supersonic molecular carrier gas cluster source. The magnetic-bottle photoelectron spectrometer's resolution is about 0. 1 eV for 1 eV photoelectrons. The adiabatic electron affinity energies of neutral clusters and some features relative to their excited states can be obtained from the spectra，i. e. ，from the anion's spectra，not only the features of the anion but also the neutral clusters' features can be investigated. The detailed design，construction，and operation of the new apparatus are presented. And studied PbM-（M = Cu，Ag，Au）binary metal cluster anions，the results give clear diagram about their structures and the bond interactions. The adiabatic electron affinity energies obtained by the photoelectron spectrometer agree well with the calculated results using relativistic density functional theory（DFT）method. It show that this anion photoelectron spectrometer can be well used in studying binary metal cluster anions in the experiment condition.