An inverse photoemission system with large solid angle of detection and adjustable optical bandpass

A high-brightness, low energy electron source and dual Geiger-Muller-type isochromat photon detectors are combined to create a versatile new inverse photoemission system. The bandpass of the photon detector can be set to one of the following discrete values: 0.37+/-0.02, 0.43+/-0.02, 0.56+/-0.02, or 0.73+/-0.04 eV by using ethanol, 1-propanol, 1-butanol, or a dimethyl ether/ethanol mixture, respectively, as the detection gas(es). All of the alcohols are self-quenching and do not require the addition of a quench gas. The design of the photon detectors, the electron gun, and the circuits that perform the dead time gating are described in detail. The capabilities of the new system are illustrated using spectra from both metal (Cu) and semiconductor (Si) surfaces. (C) 2004 American Institute of Physics.