Alcator C-Mod Weekly Highlights January 14, 2013 FY2013 weeks of research operations Target: tbd Completed: 0.53 weeks Plasma Shots: 61 Research -------- "Transport and drift-driven plasma flow components in the Alcator C-Mod boundary plasma" by N. Smick, B. LaBombard and I.H. Hutchinson has been published in Nuclear Fusion. Making use of C-Mod's unique set of scanning Langmuir-Mach probes, including one on the inner-wall (WASP), this paper assembles a comprehensive picture of boundary flows and their driven mechanisms in a tokamak plasma. The paper can be found at http://stacks.iop.org/0029-5515/53/023001 Operations ---------- New charging supplies for the emergency battery backup bank for the alternator lube oil system have been installed, and the battery bank has been checked for proper operation. Post run campaign calibration of the MSE diagnostic was finished last week, and calibration of the edge Charge Exchange system has begun. Advanced Outer Divertor (AOD) ----------------------------- A COMSOL model of the divertor including disruptions analysis is now providing useful results on fields, currents, forces, and stresses. A COMSOL 3D thermal/emag/structural analysis model is under development. A mock-up of a sheet-shunt using steel plates has been completed and is undergoing analysis. Its performance during bend tests is meeting requirements for the shunt design. The design of the EF1 heat shield has been changed to be composed of 36 degree rather than 18 degree segments. This change has reduced the number of fasteners required and simplified the design. Assembly of the radiation heat shield test module is proceeding. Design of the Langmuir probe and surface probe assemblies continued. Heater jumper connections around cut-outs in the outer divertor for diagnostic views are being designed. ICRF Systems ------------ The FMIT#3 and #4 directional couplers have been successfully calibrated and tested. FMIT#3 is now tuned to 53 MHz and has produced 2 MW of power into a dummy load. FMIT#4 has been tested to 1 MW, but still requires work on the driver stage before full power at 53 MHz can be obtained. More cabling for the second set of FFTs was completed last week. The FFT computer rack is being modified to accept connections from the second set of FFT power/control racks currently under construction. Lower Hybrid Systems -------------------- A new LH FFT ferrite sample to be used for high power testing has been prepared. The ferrite is installed in the test waveguide and is ready to test. Earlier tests on a reconditioned ferrite sample in both SF6 and N2 atmospheres did not show an improvement in power handling, necessitating the development of the new sample. Diagnostic Systems ------------------ The RFQ Accelerator diagnostic team held a meeting last week with C-Mod engineers to present a design for a proposed in-situ beam target for the FY13 campaign. The target would serve to validate RFQ beam spot size and steering with magnetic fields, as well as to validate the entire diagnostic by presenting a highly characterized surface for analysis. A number of possible modifications to the target design were discussed, and further work is now taking place to refine the design. Remote Participation, Travel, and Visitors ------------------------------------------ Bob Ellis, PPPL, was at MIT last week for discussions on the AOD shunts, and the ongoing AOD heat flux analysis and overall design work. _______________________________________________ Cmod_weekly mailing list Cmod_weekly@lists.psfc.mit.edu http://lists.psfc.mit.edu/mailman/listinfo/cmod_weekly