It is a valuable reference for any vacuum system design. The report also contains the material certifications, more » design, finite element analysis, and testing for all of these seals. This report summarizes an investigation of the metal vacuum seals that include the metal C-seal, Energized Spring seal, Helcoflex Copper Delta seal, Aluminum Delta seal, delta seal with limiting ring, and the prototype of the copper diamond seals. In addition, it is desirable to simplify the installation and thereby also simplify the maintenance required. The vacuum joints between flanges must have reliable seals to minimize the leak rate and meet vacuum and electrical requirements. Vacuum seals are very important to ensure that the Spallation Neutron Source (SNS) Linac has an optimum vacuum system. The incidence of failures already encountered, however, has made apparent the importance of routine leak testing of encapsulated sources. A review of the possible causes of leakage, and of the standard capsule design, fabrication, sealing and initial and subsequent leak testing, has resulted in recommended changes to reduce the probability of future capsule failures. Subsequent investigation of other sealed sources in the United States revealed that thirteen of more » 200 standard teletherapy capsules had developed leaks. This leak resulted in from 30 to 100 mc of activity being released before it was detected. Late in 1958, a standard capsule source at the Oak Ridge Institute of Nuclear Studies (encapsulated 1.5 years earlier with Co/sup 60/ metal pellets) developed a leak. One feature of the standard capsule was believed to be its tight seal and its ability to maintain tais integrity. Teletherapy sources encapsulated in the United States and Canada from 1954 to 1959 were generally of the standard, single capsule, sealed type.

Cobalt 60 capsule