--===============1644579456== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit You are not allowed to post to this mailing list, and your message has been automatically rejected. If you think that your messages are being rejected in error, contact the mailing list owner at psfc-owner@lists.psfc.mit.edu. --===============1644579456== Content-Type: message/rfc822 MIME-Version: 1.0 Received: from psfcsv1.psfc.mit.edu (localhost.localdomain [127.0.0.1]) by psfcsv1.psfc.mit.edu (8.13.1/8.13.1) with ESMTP id k8JE3eVZ029159; Tue, 19 Sep 2006 10:03:40 -0400 Received: from [198.125.179.53] (alcpc15.psfc.mit.edu [198.125.179.53]) (authenticated bits=0) by psfcsv1.psfc.mit.edu (8.13.1/8.13.1) with ESMTP id k8JE3bY6029153 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Tue, 19 Sep 2006 10:03:37 -0400 Message-ID: <450FF8B9.1070801@psfc.mit.edu> Date: Tue, 19 Sep 2006 10:03:37 -0400 From: Jim Irby User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) MIME-Version: 1.0 To: cmod_weekly@lists.psfc.mit.edu Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.54 on 198.125.176.238 X-Scanned-By: MIMEDefang 2.54 on 198.125.176.238 Subject: [Cmod_weekly] Alcator C-Mod Weekly Highlighs X-BeenThere: cmod_weekly@lists.psfc.mit.edu X-Mailman-Version: 2.1.5 Precedence: list Reply-To: irby@psfc.mit.edu List-Id: C-Mod weekly reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cmod_weekly-bounces@lists.psfc.mit.edu Errors-To: cmod_weekly-bounces@lists.psfc.mit.edu Alcator C-Mod Weekly Highlights September 18, 2006 FY2006 weeks of research operations: JOULE target: 14 weeks Completed: 16.7 weeks Physics ------- David Ely, a student working with Krill Zhurovich in the Undergraduate Research Opportunities Program (UROP) at MIT has extended and improved the fitTS program that allows density and temperature profile data from various diagnostics to be fit with smoothing curves. An extensive set of options is available for controlling the fits, and the fits between core and edge diagnostics can be linked. Operations ---------- We have prepared the alternator for the scheduled minor inspection to take place early this week. Inner covers have been removed so that a visual inspection can be made before hi-pot tests are begun. Electrical connections have been removed to isolate the components that will be tested. A final design meeting on the new B-Hor flange was held last week. Fabrication of the new flange can now begin. Lower Hybrid System ------------------- The proposed design for the 2nd lower hybrid launcher uses e-plane rather than h-plane cuts in the waveguide. A section of waveguide with an e-plane cut and the tapers required in the launcher has been fabricated and successfully tested. The waveguide section has low reflectivity and losses near the theoretically predicted value. Cryopump -------- Testing of the prototype cryopump in the vacuum test stand has been completed. The final test was a programmed breach of the vacuum chamber resulting in a rapid vent to atmosphere. The gas pressure in the liquid helium exhaust line remained at acceptable levels during the vent, and no leaks developed in any of the cryopump components. We believe this test was a worst case simulation of a loss of vacuum event in C-Mod. The testing program also included development of an efficient scenario by which the cryopump could be regenerated between shots. The process that was developed requires only seven minutes and will easily fit in the time between C-Mod shots. ICRF Systems ------------ Two of the four new crowbar trigger chassis have been installed in FMIT#1. A third chassis is complete and will be installed in FMIT#2 as soon as the fourth chassis is complete. Installation of these crowbar units will result in all four FMIT transmitters having the same upgraded crowbar trigger system. Work continues on the new rf control system and upgrades to the rf data acquisition hardware. A dynamic load assembly for testing the fast ferrite tuner at low power has been fabricated. It will be able to switch the load on the FFT faster than the FFT can respond and will allow extensive tests of the feedback control system to be made. Diagnostics ----------- During his last visit to MIT Perry Phillips, UT-FRC, measured the phase sensitivity of the IF system in the FRCECE diagnostic. During the last campaign, phase measurement of the FRCECE signals yielded enigmatic results which will be reported at this year's APS-DPP meeting in a poster entitled "ECE Temperature Fluctuations associated with EDA H-Mode discharges in Alcator C-Mod." To support this research, a post-campaign phase calibration was critical. In the calibration, an 80kHz signal was inserted right after the RF detector in a number of channels. The phase difference was measured for different signal levels. No differences larger than the statistical uncertainty were found. This supports the validity of the interior, fluctuation measurements observed via FRCECE in the EDA plasmas. Visitors and Travel ------------------- David Mikkelsen, PPPL, attended the TTF meeting in Marseille, Sept 4 to 7, and presented "Dimits shift in gyrokinetic simulations at high and low collisionality", which included analysis of C-Mod EDA discharges. _______________________________________________ Cmod_weekly mailing list Cmod_weekly@lists.psfc.mit.edu http://lists.psfc.mit.edu/mailman/listinfo/cmod_weekly --===============1644579456==--