Alcator C-Mod Weekly Highlights August 2, 2004 FY 2004 weeks of operation planned: 18 weeks, completed: 18.9 weeks. We are currently up-to-air with the primary goal of installing the lower hybrid launcher. In addition, a large number of invessel activities are ongoing in support of ICRF and diagnostic systems. Maintenance and upgrades to diagnostic and power systems are also in progress. Operations ---------- We continued to clean plasma facing components last week. Tile modules have been removed from the vessel and wiped down with distilled water to remove boron compounds. The modules have also been ultrasonically cleaned to remove deposits from between tiles and on support plates. The cleaning of the modules will be completed with a vacuum bake before installation invessel begins. We also continued assembling the inner wall modules using the new moly tile locking tabs. Power Systems ------------- An inventory of electronic cards used in the alternator drive excitation system has been made to ensure that spare cards will be available during the next run campaign. Lower Hybrid System ------------------- The new furnace has been commissioned and will be ready for initial brazing tests early this week. New 3-window prototypes and alumina windows are in-house and will be used for tests later this week. Three sets of the three different microwave probe housing configurations have been fabricated in the machine shop. Positioning pins are being fabricated in the shop for the right angle housings, and hardware was ordered and received for the other positioning and hold-down components. Initial tests of the probes indicate very good directivity. Cables for the new solenoid supplies for the klystrons were made in our shop this week and the supplies are now ready for installation. We continue to develop the klystron phase and amplitude control system. Besides calibrations of both the vector modulator and I/Q detector paths, we have begun the work needed to get calibration data into the MDSplus database. The DFOL design prototype has been completed. Both the transmit and receive portions are now working. This design uses our general purpose CPLD (complex programmable logic device) boards to substitute for our older DFOL discrete component designs. These new boards also fit the LH ACS chassis form factor, allow additional logic implementations on the same board as the DFOL, and allow optically isolated inputs, buffered outputs, or fiber-optic input/output for any input or output. Diagnostics ----------- Ron Bravenec, UT-FRC, has proposed design changes to improve the resolution of the BES diagnostic when observing the QC mode. During the last campaign, the BES diagnostic contributed new data on the QC mode measurements, but only under conditions in which the mode was optimally located. Modifications to the MSE/BES fiber dissector and use of additional fibers to increase the density and number of BES channels will allow the BES diagnostic to be more generally usefully in observing the QC mode. Spatial calibrations of the CXRS optics have been completed. Although the toroidal optical system used for the non-beam background views has moved slightly, this shift does not impact the measurements. Both optical systems used to observe the beam have maintained their alignment when compared to the pre-campaign measurements. Rachael McDermott, an MIT graduate student, has completed the analysis of beam attenuation that she and Bill Rowan derived from beam emission detected with the MSE diagnostic. Agreement with published stopping cross sections is good. The technique promises to provide a simple means for determining the beam attenuation on C-Mod without using complex penetration calculations. The new CO2 laser for the two-color-interferometer has arrived along with its control, power, and cooling systems. The laser will be setup and tested before being moved into the C-Mod cell. Travel and Visits ----------------- Miklos Porkolab, Earl Marmar, and Martin Greenwald attended the FESAC meeting on July 26, 27 in Gaithersburg, Md. Earl Marmar and Amanda Hubbard attended the FESAC priorities panel meeting also in Gaithersburg, July 27 and 28. Robert Granetz attended the APS-DPP program committee meeting held at APS headquarters in MD on 29-30 July. _______________________________________________ Cmod_weekly mailing list Cmod_weekly@lists.psfc.mit.edu http://lists.psfc.mit.edu/mailman/listinfo/cmod_weekly