TFTR neutral beam automated thermocouple monitor

Each of the four neutral beam lines on the TFTR (Tokamak Fusion Test Reactor) contains 368 type-E thermocouples used too monitor the temperature of the various water cooled surfaces that can receive beam power. The surfaces include the calorimeters, ion dumps, magnets and the scrapers. Currently, these temperatures must be checked manually by the operator any time the accel grid voltage changes by more than 10 kV. A thermocouple scanning system which automates the checking of these thermocouples during beam pulsing and provides monitoring for excessively cold water temperatures during periods when the cryogenic system is operating unattended is described. This system automatically activates the appropriate alarms, indicates out-of-limit thermocouples and, in the case of excessive temperatures, inhibits subsequent beam pulsing. The system consists of five VME-based microcomputer systems: one attached to each beam line for data acquisition and processing, and a central unit for monitoring, display interlocks, and alarms