Alcator C-Mod Weekly Highlights September 29, 2008 FY2008 weeks of research operations: Target: 15 weeks Completed: 15.7 weeks Operations ---------- We continued soldering of the new feltmetal on the TF arms. We have now finished 18 of the 20 lower arms which are the first ones needed to begin re-assembly. More feltmetal has been laser cut, and we have adequate feltmetal to stay on schedule. We will also continue silver plating of new feltmetal this week. The re-assembly of the alternator is complete. The oil lift system is being prepared for operation, as are systems required to purge the alternator housing with helium. Engineers representing the vendor responsible for the most recent inspection of the MIT alternator met with C-Mod engineers and scientists on Wednesday of last week. Results from the rotor inspection were discussed, and we expect the vendor will soon provide additional inspection data to us. Procedures are being developed for installation of new vessel heaters. Inspection and maintenance of our hi-yard has been completed by our power utility. ICRF Systems ------------ A new rf power detector is being developed for general use in our rf systems, possibly both ICRF and LH. The detector under evaluation has a 50 db+ dynamic range, and operates, with some input matching, from 50 Hz to 6 GHz. Linearity and dynamic range at the 80 MHz test frequency looks at least as good as our current detectors. Lower Hybrid System ------------------- The new copper plated splitter has been carefully inspected and is ready to install. Work continued on lower hybrid control system upgrades. Thermal analysis of the 4-way splitter continued. Diagnostics ----------- Our vendor has produced a metal retro-reflector of good quality from molybdenum for use in the new polarimetry diagnostic. This component is expected to perform well under the extreme conditions found on the C-Mod inner wall. It is currently undergoing optical testing while being cycled over a large temperature range. We also continued development of a limiting amplifier for the FIR detector signals. The limiter produces a 200 mV peak-to-peak signal over a 60 db dynamic range. Work continued on the DNB test chamber. The target plate was prepared for installation of the copper cooling tubes and the soldering of the tubes has been completed. The IR camera and mirrors are being tested and adjusted before pump-down of the target chamber. Travel and Visits ----------------- Steve Scott, PPPL, visited PPPL for discussions with the PPPL engineers regarding the MSE upgrade. Rajesh Maingi, ORNL, visited on Friday to give a PSFC seminar on the status of ELM research at NSTX. While here he met with his C-Mod collaborators [Hughes, Hubbard, Terry] to discuss a paper on an ITPA joint experiment that he is preparing for the upcoming IAEA meeting, and to plan further analysis of experimental data. Also while here he had discussions with C-Mod staff [Whyte, LaBombard, Terry, Greenwald] on approaches to the multi-machine JOULE milestones for FY09 and FY10. _______________________________________________ Cmod_weekly mailing list Cmod_weekly@lists.psfc.mit.edu http://lists.psfc.mit.edu/mailman/listinfo/cmod_weekly