Alcator C-Mod Weekly Highlights January 11, 1999 The Power Systems Group completed the checkout of the alternator instrumentation and CAMAC systems last week. All power systems are now ready for operation. The alternator, which is now on turning gear, will be brought up to full speed this week and be ready to provide power for magnet tests late in the week. Our main focus of activity continued to be the HEAT system last week. Now that the wiring is complete, we are powering up one set of heaters at a time and verifying proper feedback control. Completion of this system is now the critical path to plasma operation since we can not bake the vessel or cool the magnets until the HEAT system is running reliably. The modifications for the DNB controls continued. Design of the grid drive control board for the Mod/Reg is complete. The new chassis to accommodate the new control electronics for the the Mod/Reg tube is nearing completion while the low voltage control chassis was completed and installed. The Core Thomson Scattering system was aligned and calibrated last week. The machine was backfilled with argon and data was obtained at several fill pressures. The ECDC system was turned on briefly to verify proper operation of the new waveguide run. The upper TCI mirror and beamline has been installed and purged with GN2. Alignment of the TCI system will begin this week. We are in the process of connecting and debugging the new Fast MHD coils. Sixty-two of the 65 coils signals are available, 30 of which have been connected to 1 MHz sampling digitizers and 6 to 2 MHz sampling digitizers. Presently, they are connected without amplifiers, which are still in production. The coils on one limiter were calibrated without amplifiers, and a resonance was found centered about 700 kHz, which is at the upper limit of Alfven eigenmodes measured to date. With the amplifiers at the machine end of the cable, the resonance is expected to shift to still higher frequencies, outside the range of interest even for these modes, which should allow clear phase differences to be measured to determine mode numbers. The Chromex spectrometer system is being checked out through the CAMAC highway. Calibration of the Reticon arrays and the new filtered diodes which have views co-linear with the VUV spectrometer have been calibrated. The midplane fast ionization gauge at G-port has been installed and brought into operation, as has the new high-sensitivity Barotron gauge at the same location. Physics: The C-Mod Experimental Program Committee approved nine MiniProposals last week for experiments to be carried out during Start-up Operations. These experiments are required for alignment and calibration of diagnostics, RF conditioning, and commissioning of new internal hardware. Travel and Visits: During his visit in Denmark over the holidays, Thomas Sunn visited Risoe National Laboratory on Jan. 5, and gave a talk on "Edge plasma phenomena measured by the x-ray imaging diagnostic".