Alcator C-Mod Weekly Highlights January 10, 2000 We continued focusing work last week on the DNB, RF, and invessel work including the re-installation of the RF antennas. Work also progressed on maintenance of C-Mod power systems. Engineering: All work was completed last week on the OH commutation switches. This work primarily involved cleaning high voltage switches, checking high voltage connections, improving some of the high voltage insulation, and generally cleaning up in and around all the racks. General maintenance also continued on the power supply breakers. Each breaker has been checked mechanically according to the GE service procedures, hi-potted, and generally cleaned up. Similar maintenance has also been completed on the TMX contactors. All high current bus connections on the TMX supplies have also been throughly checked out. Finally, another TMX supply is being brought on line as a backup supply for the alternator exciter. Invessel work included re-installation of the D and E antennas. The D-port antenna will be declared installed as soon as the final torque check is complete. Boron nitride tiles for the E-port antenna are being fit up invessel after which they will have to be baked. A fitup of the J-port antenna outside the vessel is nearly complete. Les Gereg and Joe Frangipani came up from PPPL to direct this effort. Invessel installation of this antenna will begin this week. Other invessel work included repair to the H-port flux loop mentioned last week. Inner divertor modules have been removed from the machine and are being machined to provide new views for inner wall retro-reflectors. Work also continued on a new mirror mount to be installed at A-Hor. This mirror will allow a much better TV view of the J-port antenna. Work on the DNB included continued operation of the MOD/REG supply, and commissioning of the engineering components of the CAMAC data acquisition system. On Friday, the beam supplies were operated into the beamline for the first time. Physics: Last Thursday a final design review of the new 2-D imaging bundle was held via a video conference involving PPPL, MIT, and LANL. This new diagnostic will view the edge plasma with sufficient temporal and spatial resolution to study edge fluctuations. Reviewers from PPPL included Gerd Schilling, Dan Simon, Larry Dudek, Bob Parcell, Steve Raftopolous, Dave Johnson, and Stewart Zweben who was at MIT and is leading this effort. Jim Terry, Earl Marmar, Jim Irby, Bob Childs, Rejean Boivin, and Brian LaBombard from MIT, and Ricky Maqueda from LANL also participated. A first meeting of a new density control group took place last week. The purpose of the meeting was to open discussion on what techniques and hardware will be needed to meet the density control requirements of AT operation on C-Mod, particularly during long pulse operation with LH current drive. Experiments to run during the next campaign that would shed light on particle control issues were discussed, as were new wall conditioning and pumping techniques. Travel and Visits: Stewart Zweben, Les Gereg, and Joe Frangiapani visited from PPPL last week as mentioned earlier. On January 4th Thomas Pedersen gave a talk at Risoe National Laboratory in Denmark entitled "Impurity transport phenomena in the H-mode transport barrier region in Alcator C-Mod."