Biasing, acquisition, and interpretation of a dense Langmuir probe array in NSTX

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3490025· OSTI ID:22055854

Jaworski, M A; Kallman, J; Kaita, R; Kugel, H; LeBlanc, B; Marsala, R ^[1]; Ruzic, D N ^[2]

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1. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)
2. Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 60181 (United States)

A dense array of 99 Langmuir probes has been installed in the lower divertor region of the National Spherical Torus Experiment (NSTX). This array is instrumented with a system of electronics that allows flexibility in the choice of probes to bias as well as the type of measurement (including standard swept, single probe, triple probe, and operation as passive floating potential and scrape-off-layer SOL current monitors). The use of flush-mounted probes requires careful interpretation. The time dependent nature of the SOL makes swept-probe traces difficult to interpret. To overcome these challenges, the single- and triple-Langmuir probe signals are used in complementary fashion to determine the temperature and density at the probe location. A comparison to midplane measurements is made.

• OSTI ID: 22055854
• Journal Information: Review of Scientific Instruments, Vol. 81, Issue 10; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
CURRENTS
DENSITY
DIVERTORS
ELECTRON TEMPERATURE
FLEXIBILITY
ION TEMPERATURE
LANGMUIR PROBE
MONITORS
NSTX DEVICE
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA SCRAPE-OFF LAYER
SIGNALS
THERMONUCLEAR REACTORS
TIME DEPENDENCE