No abstract

An UHV apparatus has been designed and constructed for studying the interaction between adsorbates and photons. Since a variety of light sources and experimental geometries are used in these studies, the system was designed to be as flexible as possible. The system is put on a single frame so that it can be transported from one photon source to another. A compact, exchangeable, high-pressure cell is designed to provide easy access for photons to the crystal. To allow the study of small poly-atomics the following combination of detection techniques are installed: thermal desorption spectroscopy (TDS), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) and reflection - adsorption infrared spectroscopy (RAIRS). Furthermore, a sample exchange system in combination with liquid nitrogen sample cooling is incorporated. The exchange system allows three samples to be stored in the main chamber. The sample exchange capability does not restrict the cooling capabilities - 85 K within an hour after turning on the liquid nitrogen flow and 85 K within minutes after flashing to 800 K.