CHAPTER 3: CONSTRUCTION Click on any of the links below to download high resolution pdfs of any figure FIG. 3.1: Thermal conductivity of selected classes of materials FIG. 3.2: Thermal expansion of selected construction materials FIG. 3.3: Volumetric heat capacity (at constant pressure, CP) of several types of materials at cryogenic temperatures FIG. 3.4: Temperature dependence of the yield strength of several cryostat materials FIG. 3.5: Example of choosing materials that will tighten a joint on cooling FIG. 3.6: Burn-down lip machined into a circular plate to increase welded-joint reliability FIG. 3.7: Bulk thermal conductivity of common solder materials FIG. 3.8: Joint designs with large soldered-surface areas for mechanical strength FIG. 3.9: Schematic illustration of a mechanical test apparatus, showing titanium pull rod and stainless-steel (SS) load-reaction tube FIG. 3.10: Geometry of beams and circular plates FIG. 3.11: Vacuum requirements for various applications FIG. 3.12: Metal C-ring seal FIG. 3.13: Design of the ConFlat® flange seal FIG. 3.14: Indium O-ring seal designs FIG. 3.15: Cut-away view of indium O-ring cryogenic vacuum compression seal FIG. 3.16: Conductance of cylindrical tubes at room temperature under conditions of free molecular flow FIG. 3.17: Examples of correct and incorrect welding practice for vacuum applications FIG. 3.18: Degassing rate for untreated metals, compared with Neoprene ™ plastic and Araldite™ epoxy FIG. 3.19: Vapor pressure curves of metals: high-vapor-pressure metals FIG. 3.20: Permeation constant K for helium through several Corning™ <em>glasses</em> as a function of temperature FIG. 3.21: Permeation constant for helium gas through several ceramics as a function of temperature FIG. 3.22: Permeation constant K for hydrogen through several metals as a function of temperature References: Listing of all References for Chapter 3 Figures
