| Autor: |
Gupta, Deepak K., Fonck, Raymond J., McKee, George R., Schlossberg, David J., Shafer, Morgan W. |
| Předmět: |
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| Zdroj: |
Review of Scientific Instruments; Oct2004 Part I & II, Vol. 75 Issue 10, p3493-3495, 3p |
| Abstrakt: |
An upgraded beam emission spectroscopy (BES) system has been deployed to access low amplitude turbulence regions near internal transport barriers on the DIII-D tokamak. Sixteen high sensitivity channels are being installed. A significant increase in total signal to noise is achieved by: (1) Increased spatial volume sampling tailored to known turbulence characteristics; (2) An increased throughput spectrometer assembly to isolate the local beam fluorescence, coupled to new large area photoconductive photodiodes; (3) A new sharp edge interference filter designed to optimize detection of the beam emission plus a significant fraction of the thermal deuterium charge exchange. A new data acquisition system has been installed, providing an eight times increase in integration time or an increased sample rate. Preliminary results from the upgraded system show a signal enhancement of greater than an order of magnitude. A clear broadband density fluctuation signal is observed in H-mode discharges with the upgraded BES system, demonstrating the significant performance enhancement. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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