9. Vacuum Techniques

Abstract

Publisher Summary This chapter discusses some vacuum techniques. As the name “vacuum ultraviolet” (VUV) implies, this radiation must be transported and used in a vacuum environment. The chapter includes the information that a researcher needs to house an experiment to take an advantage of VUV radiation. It is assumed that the source is either a synchrotron or a laboratory source that will have its own vacuum requirements. The chapter mentions the necessity of having a working knowledge of fore, sorption, cryo, ion, titanium sublimation (TSP), and diffusion pumps; right angle, gate, and leak valves; and thermocouple and ion gauges. In addition, familiarity with residual gas analyzers (RGA) and helium leak detectors is also helpful. The design of vacuum environment chambers to house VUV experiments fall into three main categories depending on their use: gas phase experiments including metal vapors, solid state experiments, and beamline optics. The type of pump for the gas phase experiment must be selected with an eye toward the type of sample under investigation. For atmospheric and similar nonreactive gases, high-speed turbo, or cryopumps, are the most effective. One of the most time consuming chores in setting up a vacuum-based experiment is isolating vacuum problems. The major problem with the optics is their exposure to high intensity, high energy radiation for prolong periods of time. Several techniques have been developed to remove the carbon contamination either in situ or with the optics removed.