Alcator C-Mod Weekly Highlights October 5, 2009 FY2009 weeks of research operations (Complete) Target: 9 weeks Completed: 9.1 weeks Discharges: 1165 FY2010 weeks of research operations Base Target: tbd ARRA Target: 6 weeks Completed: 0 weeks Operations ----------- Last week was a maintenance week at Alcator C-Mod. No plasma operation was planned. Plasma operations are planned to resume this week. Program Planning ---------------- A meeting of the Experimental Program Committee was held on Thursday, Oct. 1. Four experimental proposals were reviewed and approved. Priorities for the three weeks of run time planned before the APS meeting were discussed, and a plan for the next week of operation determined. Data Acquisition and Computation -------------------------------- Fifteen new Linux workstations have been put into service in the C-Mod control room. These computers are replacements for obsolete workstations purchased more than 6 years ago. Diagnostics ----------- The new, high frequency FRCECE (Electron Cyclotron Emission) receiver was installed last week. A new power supply for the unit and new wave guide were also installed . The IF unit for these channels was tested. This high frequency receiver is intended for 16 channels of ECE measurements from the plasma core. The outer 16 channels have been in operation since the beginning of the campaign. The upper optical table for the polarimeter diagnostic was successfully installed in the cell last week. This table supports steering and focusing mirrors needed to direct the FIR beams to retro-reflectors on the inner wall. An auto-leveling laser transit was used to position the table so that the FIR beams can be scanned approximately +-1 degree around an angle perpendicular to the toroidal magnetic field. Preparations are being made for the move of the lower optical table into the cell that supports the FIR lasers, detectors, and other optical components. This move will take place once tests of the single chord prototype in the lab are complete. ICRF Systems ------------ The J-port antenna transmission line network in the cell was removed and the configuration modified to allow installation of polarimeter optical table to be completed. The resonant loop configuration was changed to allow current drive phasing in addition to heating phase. We also performed maintenance on FMIT#4 screen supply and the FMIT#1 breaker charging circuit. Work on the new ICRF antenna continues. We have placed orders for the inconel from which the antenna straps will be machined, and for stainless steel needed for qualifying the antenna strap fabrication process. Lower Hybrid System ------------------- Successful high power tests were conducted last week of the e-beam welded waveguide. No faulting occurred at power levels of up to 240 kW with 200 ms long pulses. This power level is well above what is expected during operation on C-Mod. We expect to begin e-beam welding of waveguide, 4-way splitters, and transformers this week. A trip to the vendor selected for the e-beam welding was made last week to discuss the procedures and processes required, and the schedule. Travel and Visitors ------------------- Catherine Fiore, Amanda Hubbard, Jerry Hughes, and John Rice participated in the H-mode Workshop at PPPL last week. Their presentations were: Fiore: Rotation and Transport in Alcator CMod ITB Plasmas Hubbard: Improved L-mode plasmas with decoupled energy and particle barriers in Alcator C-Mod Hughes: H-mode pedestal regulation experiments on Alcator C-Mod Rice: Recent Progress in Rotation and Momentum Transport by the ITPA Transport and Confinement Group Randy Wilson (PPPL) visited MIT on October 1-2 to work with the lower hybrid group on simulations for future experiments, particularly LHCD in H and I mode discharges. Michael Bell (PPPL) visited MIT on Friday to present a PSFC Seminar entitled "Plasma Response to Lithium-Coated Plasma-Facing Compenents in NSTX". He also had discussions with C-Mod physicists. Paul Bonoli attended a Tutorial Workshop on using the Integrated Plasma Simulator (IPS) that was held at Oak Ridge National Laboratory on September 29, 2009. The IPS is a framework that has been developed by the SWIM Prototype Fusion Simulation Project (FSP) that allows multiple physics components such as the transport code TSC, the Monte Carlo neutral beam code NuBeam, full-wave ion cyclotron solvers such as AORSA and TORIC, and Fokker Planck codes such as CQL3D to be run concurrently on massively parallel computing platforms such as the Franklin computer at NERSC. Paul Bonoli, John Wright, and Jesus Ramos also attended a meeting of the SWIM FSP Project that was held at ORNL from September 30 - October 2, 2009. Paul and Jesus attended the meeting in person and John attended the meeting remotely from MIT. John Wright gave a talk related to work he has been doing on XML applications for data input to simulation codes. Paul gave talks on plans and progress for using the IPS to perform simulations of current profile control experiments in Alcator C-Mod using lower hybrid and ion cyclotron mode conversion current drive. Jesus gave a talk on work he has done on a closed fluid and drift-kinetic electron formulation for slow MHD. Ian Hutchinson attended the Fission-Fusion Hybrid ReNeW workshop in Gaithersburg Maryland. He was the spokesman for the skeptics panel. _______________________________________________ Cmod_weekly mailing list Cmod_weekly@lists.psfc.mit.edu http://lists.psfc.mit.edu/mailman/listinfo/cmod_weekly