Alcator C-Mod Weekly Highlights May 17, 2002 Effort focused this week on preparations for pumpdown. Work also continued on ICRF, LH MIE Project, and RFX DNB systems. Operations ---------- Invessel work this week included final assembly of the ICRF antennas, and calibrations and checkout of many invessel diagnostics. Thermocouples have been added to all the antennas and will be read out with our new fast TC scanner. The new thermocouples behind the inner divertor are operational and are already being read out through the scanner. The visible continuum array, TV views, H_alpha, and CXRS diagnostics, among others, were also aligned and calibrated this week. First pumpdown is expected early next week. The cryostat and bus tunnel have been sealed and the GN2 purge system was checked out and debugged. It will go into full time operation early next week. We continue the migration of many of our analysis routines to the Linux based computers. EFIT is now fully operational on the new machines. Some routines, the TCI analysis for example, are running 2.5 times faster under Linux than on our fastest Alphas. The Hybrid Plasma Control Systems has been checked out and is operational. The magnet power systems are being brought back into operation. Bus Rowgoskis are being calibrated, ground fault fuses and current monitors checked and calibrated, and bus voltage instrumentation checked. The bus will have a final retorque at the end of next week. Lower Hybrid MIE Project ------------------------ At PPPL, lab testing of the Lower Hybrid launcher prototype is continuing. The dielectric constant of the ceramic window material has been measured at 4.6 GHz, and a thickness has been specified for final fabrication. The window "bricks" are now on order. Ethan Schartman, a graduate student at Princeton University, will be working on LH modeling and code development for his second year theory project. He will develop a parallel version of the LSC code to use in scenario development for Lower Hybrid AT experiments on C-Mod. At MIT, the TPS Optical Interface Board 2 has been completed. HVPS commissioning is progressing. The vendor estimates they will be ready for acceptance tests within the next two weeks. ICRF ---- We continue to work on the control and fault electronics. Calibrations continue on the new phase demodulator boards. Phase plots indicating output voltage vs input phase have been completed for all the boards. Cabling of the new racks is well underway. All invessel work on the antennas was completed this week including installation of the new thermocouples, and re-installation of the rf magnetic probes and BN tiles. RFX DNB ------- The DNB was operated briefly this week to test operation following the repositioning of some of the DNB equipment. The DNB duct and vacuum interface to the torus was completely assembled. The optical bench for beam spectroscopic monitoring was completed and installed. The new fueling system is nearing completion. The DNB was aligned relative to the tokamak this week using an invessel laser to illuminate the source grids. Assembly of the CXRS feedthroughs was completed. The shutter controls were installed and tested, and the shutter position calibrated. The CXRS toroidal channels were spatially calibrated. The CXRS periscope at F-Top was installed. Alan Lynn, UT-FRC, provided in-vessel support for CXRS, MSE, and BES shutter assembly and for CXRS calibration. He also began assembly of the refurbished ECE high resolution radiometer. He and Perry Phillips, UT-FRC, will complete this next week. This was Alan's last "visit" prior to his taking up residence in Boston in June for the duration of the campaign. Ron Bravenec, UT-FRC, collaborated with C-Mod personnel on assembly of the BES/MSE optics and continued BES fiber polishing begun by Matt Sampsell a few weeks back. Travel and Visits ----------------- Martha Redi, PPPL, was at MIT May 13-17, working with Catherine Fiore and Paul Bonoli on gyrokinetic analysis of off-axis RF heated plasmas, which exhibit internal transport barriers. Gerrit Kramer and Jay Kung, also PPPL, were at MIT May 15-17 to install the two new 130 and 140 GHz reflectometer channels for fluctuation measurements farther up the edge pedestal.