Remotely controlled illumination system for TFTR in-vessel inspection

Abstract

Internal components of the Tokamak Fusion Test Reactor (TFTR) vacuum vessel are inspected routinely during nonoperational periods using in vacuo illumination probes in conjunction with a periscope/camera viewing system. The probes presently in use must be inserted manually by personnel in the test cell, and thus are not suitable during the DT operating phase of TFTR. A new probe concept was developed which is compact, mechanically robust, and remotely operated. Each probe consists of four 650 W tungsten–halogen lamps mounted on an inconel reflector and a rotatable, cylindrical shutter which protects the lamps from deposits during plasma operation. Six probes will be permanently mounted inside the vacuum vessel at top and bottom ports which are distributed to provide the most uniform illumination practicable. The probe design and results from prototype testing will be presented.