Alcator C-Mod Weekly Highlights May 5, 1998 We continue to develop the inductive heating technique for replacing TF feltmetal. A test fixture with an array of thermocouples and associated data acquisition equipment has been fabricated and is being used to determine temperature profiles during the soldering process. Different coil geometries will also be tried so that an optimized heating profile can be determined. The TF core has been repositioned on a new stand so that cleanup and replating activities will be easier to perform. A detailed survey of feltmetal thickness on the upper and lower horizontal arm inner joints was finished. The upper horizontal arm feltmetal averaged .004" thinner than the lower, consistent with the more advanced wear found there. We continued to progress in the development of the DNB for C-Mod. The fault circuitry in the arc/filament/snubber voltage feedback and monitoring system was completed and calibrated. The breakdown voltage for the oil in the tank shared by arc/filament/snubber supplies was found to be 20 kV and conditioning of the oil was begun using the same techniques as for the accelerator supply and for the Mod/Reg isolation transformer. The design of the logic boards in the arc/filament/snubber interface to the MCL was completed. Calibration and testing of the control system for arc detection was begun. A review of the integration of the beam firing and conditioning cycle with the C-Mod firing cycle was held to assist in finalizing the remaining hardware and software required. We continue to look for the cause of the FMIT#4 crowbar. We have tested the driver into a dummyload without a fault. This test suggests the problem is in the final stage. We will begin disassembly midweek for a visual inspection. If no arc indications are found upon inspection, we will replace the tube with a spare and test the transmitter again. This change should allow us to determine if the arc is in the tube or the cavity. We have also begun testing the control system for FMIT#3. Testing of control boards also continues. Martin Greenwald, Ian Hutchinson, Earl Marmar, Spencer Pitcher, Miklos Porkolab, Joe Snipes, and Steve Wolfe attended the Next Step Conference in Madison Wisconsin last week. Miklos Porkolab gave a presentation on ATBX, or Advanced Tokamak Burning Plasma Experiment, a reduced size, 50% cost, version of ITER.