Alcator C-Mod Weekly Highlights January 17, 2005 FY 2005 weeks of research operation planned: 14 weeks, completed: 0 weeks. The Alcator C-Mod vacuum vessel has been pumped down and is undergoing a series of leak-checks in preparation for a vacuum bake and electron cyclotron discharge cleaning (ECDC). Operations ---------- Alcator C-Mod was pumped down on Thursday of last week. Leak-checks continued through the weekend and into Monday of this week. Several leaks have been found and are undergoing repair. The CRYO, HEAT, and ECDC systems are being prepared for operation. These systems are needed to bake the vessel and begin cleanup of the walls. A several day long bake period will begin as soon as the machine is leak free. A set of survey pictures of invessel hardware just before pumpdown can be found at http://www.psfc.mit.edu/cmod/operations/EngImages/CmodImages.asp?ref=/INVESSEL/2004/pumpdown_survey/ A GN2 purge of the C-Mod cryostat was begun on Thursday of last week. Moisture levels in the cryostat were well below 100 ppm by Monday morning indicating the cryostat was well sealed and dry and could support introduction of liquid nitrogen. The alternator has been brought into operation at low speed as a complete systems checkout begins. We are working with a consultant to verify proper settings for the protection relays. We continued migration from CAMAC to CPCI with installation and checkout of new systems in the bus instrumentation, alternator, and long pulse racks. Lower Hybrid System ------------------- The splitter and phase-shifter waveguide assembly has been installed onto the rear waveguide (rwg). Phase calibrations of this system and the rwg will begin this week. Pictures of the rwg and the waveguide assembly can be seen at http://www.psfc.mit.edu/cmod/operations/EngImages/RF/lower_hybrid/DCP_2090.JPG and http://www.psfc.mit.edu/cmod/operations/EngImages/RF/lower_hybrid/DCP_2091.JPG The drive system for moving the launcher under vacuum load has been assembled. The linear potentiometer for measuring the position of the launcher has been installed and calibrated. This information will be available to both the LH control PLC and MDSplus. The communication link between the PLC and PC in the control room has been made operational. The last of the three new filament controllers has been installed and tested in lower hybrid klystron cart 3. We have nearly completed testing of the Coupler Protection System (CPS). The PLC and all I/O lines have been verified for proper operation. All CPS rf cards have been tested. This system is now ready to be installed in the cell where the CPS data acquisition components will be tested (CPCI). ICRF System ----------- Installation of new choke inductors to better protect the FMIT high voltage lines continued last week. Re-assembly of the transmitters has begun. Characterization of the J-Port antenna with the new vacuum feedthroughs was completed. Long Pulse DNB -------------- All I/O lines for the control of the new DNB power system have been configured, connected to the PLC, and tested back to the interconnect enclosure in the cell. The IOC relay is being installed in the 4160 VAC circuit breaker. Once installation is complete, we can test the control of the entire system up to the 480 VAC distribution panel in the cell. Several new cable trays have been installed below the deck around F-port in order to accommodate the cabling for the new beam. The Russian team has begun disassembly of the new long-pulse DNB and is preparing it for shipment to MIT. Diagnostics ----------- The interferometer section of the new polarimeter/interferometer diagnostic became operational last week. Layout plans for the lasers, Bragg cells and associated optics can now be firmed up. Travel and Visits ----------------- Randy Wilson and Nevell Greenough, PPPL, were at MIT last week directing the assembly of the rwg splitter and phase-shifter waveguide assembly. Miklos Porkolab attended the "Center for Multi-Scale Plasma Dynamics " Winter Workshop and School at UCLA and lectured on phase contrast imaging techniques to measure mode converted RF waves, Alfven wave cascades and low frequency turbulence. Liang Lin, a C-Mod graduate student, also attended. Approximately 30 students, and another 15 to 20 researchers and professors from various regions of the US attended the workshop. _______________________________________________ Cmod_weekly mailing list Cmod_weekly@lists.psfc.mit.edu http://lists.psfc.mit.edu/mailman/listinfo/cmod_weekly