Development of lithium beam emission spectroscopy as an edge fluctuation diagnostic for DIII-D
As part of the DIII-D diagnostic complement designed to address L-H transition physics issues, we have developed and commissioned a diagnostic neutral lithium beam and multichannel fluorescence detection system to investigate the edge plasma density and its associated fluctuations. The use of lithium offers several advantages for tokamak edge beam emission spectroscopy (BES) studies, including large excitation cross sections which are relatively insensitive to temperature variation, the availability of the 670.8 nm resonance line well separated from most plasma line emission, and the suitability of modest beam energies and currents to probe even dense H-mode plasmas. These features permit measurements of collisionally induced fluctuations to be obtained with good spatial (<1 cm) and temporal (<10 {mu}s) resolution. The improvements over previous lithium beam diagnostics which were required to successfully make these measurements in a large, remotely controlled machine environment will be discussed, a long with the present state of the diagnostic system and our plans for future improvements of this technique.
- Research Organization:
- General Atomics, San Diego, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-89ER51114; FG03-90ER54081
- OSTI ID:
- 10176765
- Report Number(s):
- GA-A-21718; CONF-940552-24; ON: DE94017517; BR: 35AT10020/35KC07000; 35AT05000/AT0530030
- Resource Relation:
- Conference: 10. topical conference on high-temperature plasma diagnostics,Rochester, NY (United States),8-12 May 1994; Other Information: PBD: May 1994
- Country of Publication:
- United States
- Language:
- English
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An edge density fluctuation diagnostic for DIII-D using lithium beams
Edge density fluctuation diagnostic for DIII-D using lithium beams