Positron Annihilation Induced Auger Electron Spectroscopy(PAES) has several advantages over those excited by X-rays
high energy electrons or neutrons
such as excellent surface selectivity
high signal-to-noise ratio
low radiation damage
etc.A physical design of time of flight PAES(TOF-PAES) apparatus based on the Beijing Intense Slow Positron Beam(BIPB) is described in this paper.The positrons and electrons are transported in a 4×10-3 T uniform magnetic field
and the gradient of magnetic field is designed to parallelize the Auger electrons emitted with 2π angle.The Auger electron energy is adjusted by a Faraday cage to optimize the energy resolution