In-vessel maintenance on the IGNITEX experiment

An in-vessel remote maintenance system (IVRMS) for the IGNITEX ignition tokamak first-wall system is discussed. The design emphasizes simplicity, reliability, and low cost. Diagnostic hardware, power supplies, and fueling and vacuum systems will be located after the primary shielding so that they will be accessible for maintenance and adjustment between pulses. The essential tasks to be performed by the IVRMS are inspection of first wall and diagnostic penetrations for damage and vacuum leaks and repair of damaged areas by welding and beryllium-spray-coating techniques. Its main element is an articulated boom with nine degrees of freedom, used to position the end effectors to the desired location. Positioning of the end effectors with poloidal precision is obtained by using a guiding jig which will be deployed and attached to the first wall. The control module will be teleoperated with tach-learn capability. A self-transporting storage chamber with internal decontamination capability is envisioned. The feasibility of using frameless, lightweight, self-contained actuator modules with molded, carbon-fiber links is being studied. This design can result in a stiff articulated boom with a compact cross-sectional area suitable for use in the IGNITEX device.<>