Alcator C-MOD Weekly Highlights March 18, 1997 Last Saturday the upper dome was lowered into place, and each of the 48 drawbars was tensioned to the 500,000 lbs required to support the forces generated primarily by the TF magnet. Now that the machine proper is complete, we are working to install the curved bus, TF bus, horizontal ports, cooling lines, RF antennas, and invessel components. In addition, we have continued a wide range of continuity, ringing, and resistance tests on the magnets and coaxes. The bus tunnel has been moved back into position, and many of the tests that have been performed in the experimental cell, will soon be conducted from the power room so that other bus components and diagnostics can be tested. Invessel work is going quickly. The upper ceiling modules have been reinstalled. These modules were modified to accept the new inboard periscopes. Gas capillary tubes have been repaired and in one case relocated. Studs have been added to support the new invessel telescope and the conduit for the new edge XUV diode array, and to increase the stability of the TTCI mirror mount. Coaxes for the full limiter probes have been reinstalled. Cables for the inner divertor probe array have also been reinstalled. This last installation was required before some of our disruption/halo diagnostics could be put back into place. Modifications to the wall tiles required before installation of the new RF probes can proceed have been completed. The tangentially viewing XUV diode arrays are complete and are undergoing final testings and alignment. The edge array, already installed invessel inside the full RF limiter between F and G ports, will measure radiated power at the edge of the plasma at the midplane. This 19 channel diode array will have a nominal 2 mm spatial resolution and span approximately 4 cm of the edge plasma. The second array, with a 16 channel detector installed in the same housing as the core foil bolometers, will look at the core plasma, with a nominal radial resolution of 1 cm. Both arrays are capable of a frequency response greater than 100kHz. Since these new arrays are insensitive to neutral particles, they will, in combination with the foil bolometer array, provide new information on the power loss due to charge exchange neutrals. Work continues on the installation of the ACCEL supply for the DNB. A controller for the new supply has been selected and modifications to this unit are now underway. A method for coordinating the ACCEL supply turn-on with the MOD/REG timing has been chosen to minimize the voltage drop across the MOD/REG tube. The implementation of the control system can now proceed with this strategy in mind. Analysis of the oil for the ACCEL supply and for the filament/bias supply has been arranged. CAMAC equipment for DNB control, and a temporary support for the beamline to be used during testing have both arrived from the University of Texas. The power systems group continues to ring out the power supplies. The OH1 shakedown has been completed. The regulator, gates, crowbar, and all fault detection circuitry have been checked. The OH2 upper and lower regulators have also been checked, and we are beginning work in the converter and crowbar cabinets. Crowbar trigger circuits for transmitters #3 and #4 have been completed. The water supply for transmitter #3 FPA has been connected. We are fabricating transitions and flanges for the FPA anode cooling pipes for transmitter #4. The final assembly of these components will be done at PPPL. John Gumpus is visiting this week from PPPL to continue his work with us on the new RF transmitters. Mark May from the Johns Hopkins University was at C-Mod in preparation for the installation of the new XUV divertor monochromator and for small modifications of the core plasma "Moly Monitor". Ben Welch and Jim Weaver are here from the University of Maryland directing installation of there spectroscopy diagnostics. G. Cima from the University of Texas was here discussing ECE diagnostics. Amanda Hubbard was at PPPL last week serving on the selection committee for the National Undergraduate Fellowship program in Plasma Physics and Fusion Engineering. Bruce Lipschultz was in San Diego at the ITER Divertor Database meeting. Earl Marmar participated in the 6th meeting of the ITER expert group on plasma diagnostics held at the Naka Joint Work Site in Japan.