Alcator C-Mod Weekly Highlights February 14, 2000 Invessel, RF, DNB, and power system work continued last week. Pumpdown, startup of vessel heater and cryo systems, and leak checking are all scheduled for the next few days. Engineering: The DNB power systems were brought into operation into the beamline last week. This operation completes our final milestone for the DNB approximately one month early. In addition, a 25 kV beam at approximately 2 amps was extracted just to test all the HV, interlock, control, and protection circuitry. Some ground loop problems were discovered during the test that will be fixed over the next few days. We are also in the process of resolving DNB personnel safety issues so that people can be allowed in the cell during DNB testing. During the first few days of operation we have not allowed anyone in the cell when high voltage was applied to the beamline. We are moving quickly on invessel work and expect closeup and pumpdown this week. Alignments, invessel cleanup, and documentation and inspections continue. The new rangefinder retro-reflectors are installed as are the tile support plates they look through. The alignment of the new retro- reflectors has been checked with a telescope from outside the C-Hor port and looks acceptable. Preparations are being made for alignment of the tangential two-color-interferometer which will occur as soon as the C-Hor flange is back in place. Invessel alignment and calibration of the visible continuum array was completed. The input periscope design has been changed, and the new system has increased light throughput, which will allow for improved time resolution. The system mirror has been slightly reoriented so that the camera view goes farther out into the scrape-off, well into the shadow of the outboard limiters. Invessel ICRF antenna activity is complete including extensive measurements of antenna tile locations and careful alignment checks. Measurements of and possible adjustments to the external resonant loops coupling the antenna current straps to the transmitters are in progress. One of the loops for the older D- and E-port antennas had previously been found to be off-resonance, and the recent J-port antenna modifications have changed its electrical characteristics sufficiently to necessitate a recheck. PPPL RF fault detectors in use at C-Mod are being modified for faster response times, and remaining transmitter upgrades are continuing. A thermocouple has been added invessel to measure the temperature of the E-port antenna with the boron nitride upper and lower tiles. The #1 and #2 transmitters FPAs, which were disassembled during the maintenance period, are nearly back in service, as checks of the FPA crowbars have been completed, and tests of the screen crowbars are underway. The MSE optics repair and calibration will be completed by Tuesday. A lens assembly motion restrainer will be added from outside the vacuum vessel early in the week of 2/14. We are finishing up work on several engineering systems in preparation for vacuum conditioning and eventual plasma operation. Improvements to the GN2 seals on the bus tunnel, cryostat, sump, and valve manifold box have been completed. Work on the heater system to protect the connectors from water intrusion will be complete by pumpdown, at which point checkout of the heaters will begin with a 35C "bakeout" for a few days. All bus instrumentation has been refurbished and checked out. Improvements to the Cryo system wiring have been completed. Calibrations to the 13.8 kV instrumentation are also nearly complete. Engineering data is flowing again between our control computers (PLCs) and our VaX cluster. Physics: On 2/7 and 2/8 of last week a Program Advisory Committee Meeting was held at MIT. Ben Carreras of Oak Ridge chaired the committee, and the other members are Philip Efthimion and Ed Synakowski of PPPL, Ray Fonck of U. of Wisconsin, Tony Leonard of DIIID, Mike Mauel of Columbia, and Claude Gormezano of Frascati. John Willis and Rostom Dagazian from OFES attended the meeting. Talks were given by Alcator C-Mod personnel and our collaborators covering nearly all aspects of the C-Mod program; the agenda included: Welcome -- Porkolab Introduction and Overview -- Marmar Advanced Tokamak Program: Goals -- Parker Modeling -- Bonoli FY2000 Experiments -- Marmar Transport: Overview -- Greenwald Core Transport -- Rowan Pedestal Physics -- Hubbard Divertor/Edge: Scrape-off Layer Transport -- LaBombard Long Pulse/AT Divertor Issues (particle and power) -- Pitcher ICRF Physics: Overview -- Wukitch Heating, Flow and Current Drive -- Schilling MHD -- Granetz Performance Enhancements -- Snipes Schedule and Run Planning -- Wolfe Experimental Facility Status, Hardware and Diagnostic Upgrades, Long Pulse Operation -- Irby Lower Hybrid RF: Hardware Plans -- Bernabei Preparation and Schedule -- Irby Budget -- Marmar/Keating In addition, a session in which questions asked by the PAC were answered was held on the second day. A quarterly review was held on February 9. Rostom Dagazian from OFES discussed various aspects of the C-Mod program with Ian Hutchinson, Earl Marmar, Jim Irby, Bill Rowan, Dave Terry, Steve Wukitch, Gerd Schilling and Joel Hosea. The discussions centered on the status and near term plans for the diagnostic neutral beam and its associated diagnostics, and on the ICRF systems. Travel and Visits: Barrett Rogers of U Md visited to deliver a seminar on edge turbulence. Discussions with members of the C-Mod team included future plans for collaboration on non-linear fluid simulations and gyro-kinetic stability calculations. Joel Hosea, PPPL, came 2/7-2/9 to discuss Lower Hybrid program issues and our coming ICRF startup. Stefano Bernabei also came from PPPL to participate in LH program discussions (as well as give a talk at our PAC meeting). Rejean Boivin was in Quebec city for the first (on site) planning meeting for the APS-ICPP meeting in next october. Plans were made for the outreach day and space allocation.