Alcator C-Mod Weekly Highlights November 7, 2011 FY2012 weeks of research operations Target: TBD Completed: 0 Plasma Shots: 0 Research -------- The Alcator C-Mod team will have 58 first-author presentations at APS-DPP 2011 (Salt Lake City, UT, Nov. 14-18). Five Alcator C-Mod Invited Talks by C. Fiore, N. Howard, E. Marmar, J. Rice, and G. Wallace will be given this year. Reviews of all these presentations will be completed early this week. At least 68 presentations at the APS meeting will reference C-Mod results. Operations ---------- Alcator C-Mod was pumped down on Saturday, Nov 4th after approximately 7 1/2 months of up-to-air activity. During this up-to-air period we have installed the new ARRA funded rotated 4-strap antenna, the Correlation Electron Cyclotron Emission diagnostic, the QCM antenna, new lower hybrid limiters, 2nd disruption gas jet, AXUV diode array, fast ion loss diagnostic, ICRF SOL reflectometer, vertical scanning probe, A/K Upper divertor probes, GH limiter thermocouples, new impurity seeding feed lines, 5th X-Ray Tomography Array, and the MSE in-situ calibration system. We have modified the CXRS periscope, bolometry arrays, and the impurity spectroscopy system. The B-Horizontal flange was modified to accommodate new diagnostics and the in-situ surface analysis RFQ accelerator beam. We have replaced the G-Horizontal port extension to improve access, the Thomson Scattering viewing dump, and the polarimeter retro-reflectors, and we have replaced, repaired, or relocated several flux loops and Bp coils. We have refurbished and cleaned windows, shutters, and outer wall components. The lower corner of the new 4-strap antenna was found to partially obstruct the spectroscopic views of the GH limiter. Switching the spectroscopic re-entrant periscope components with those of the lower hybrid launcher video view allowed the spectroscopic views to be restored while maintaining a TV view of the launcher. Modifications to the in-vessel periscope shrouds that protect the windows from boronizations were also required. ICRF Systems ------------ Each of the four ICRF transmitters has been run into dummy load at the 2 MW level. Qualification of the new driver crowbar ignitron for transmitter #3 is still on-going. Our vendor has now brazed the center conductors for the fast ferrite tuners (FFT), and the outer conductors, already brazed, have been sent out to be silver plated. We have sent the vendor a power supply pair which is currently being processed through customs. A visit to the vendor's facility is planned in early December to witness testing of the first FFT pair. Lower Hybrid Systems -------------------- Work on the Transmitter Protection System (TPS) upgrade continues. Jumper and PLC interface wiring for all three equipment racks is now complete. Wiring in the equipment rack high voltage control section is also complete. All new wiring for the TPS upgrade is now in place. Communications fibers for the TPS upgrade between the cell and setup lab were labeled and installed. Timing of the clocks for all fibers is within 20ns. Installation of all new fiber runs is complete. The Graphical User Interface (GUI) for the TPS upgrade is now complete. A fault signal emulator board provided by the SBIR vendor was integrated into a bench test setup for the TPS boards. A faulty reset button on TPS board #4 was identified and fixed. The vertical position of the LH launcher with respect to the vacuum vessel midplane was verified with a laser level measurement. The LH launcher is centered on the midplane as expected, however the GH limiter is located slightly below the midplane. New LH3 controller boards arrived from the vendor and were assembled in a test setup. Diagnostics ----------- Installation and qualification of upgraded Thomson scattering lasers commenced last week. Representatives from the laser vendor were on-site to align the internal optics and establish operation at factory specifications. One of the two units is operating within spec, and work can now begin on integrating the laser with local timing generation and data acquisition. An additional visit from the vendor will be required to complete the installation and testing of the second laser. The University of Texas DNB diagnostics upgrade continued last week. The optics for the spatially and spectrally resolved beam monitor were installed on the beam duct. The monitor will provide spatial profiles for each of the beam energy components. The data will improve predictions for beam density and profile in the plasma and may assist with beam optimization. The C-Mod Polarimeter has been upgraded from one to three chords. All three chords are operational with very good signal levels. Two reference detectors are also operational. Remote Participation, Travel, and Visitors ------------------------------------------ At the invitation of Zhejiang University, in Hangzhou, China, Miklos Porkolab participated in the Physics Department International Evaluation and Advisory Committee meeting on October 29-31. In particular, Miklos contributed to the evaluation, and recommendations for future growth of plasma and fusion physics in the Department. Jay Kung, an RF engineer from PPPL, was at MIT from Monday, 10/24, to Friday, 10/28, to setup the high frequency reflectometry channels in the lab and found them to be stable and ready for installation. Later in the week he worked with Arturo Dominguez to reinstall the system in the cell. David Beltran, ITER Organization (electrical engineering division), Francisco Gallardo, Autonomous University of Madrid, Rafael De La Calle, F4E (Fusion for Europe), and Joseph Snipes, ITER Organization, (integrated scenarios) have completed installation of the equipment required for the ITER Grounding Experiment on C-Mod. _______________________________________________ Cmod_weekly mailing list Cmod_weekly@lists.psfc.mit.edu http://lists.psfc.mit.edu/mailman/listinfo/cmod_weekly