Preinstallation testing of TFTR long pulse ion sources correlated with reliability

The operational performance of the long-pulse ion sources (LPISs) installed and operated on the Tokamak Fusion Test Reactor (TFTR) neutral beam injection system has been compared with preinstallation test data. A direct correlation between unsatisfactory performance and/or failure and preinstallation test results can be made. Upon disassembly of the LPISs, causes for the failure were found. Improved cleaning processes and inspection procedures have been implemented. More stringent testing during the assembly phase and stricter acceptance criteria for preinstallation tests have helped avoid failures. The more stringent procedures are discussed, preinstallation test data is presented, and operational reliability is described