Fringe jump analysis and implementation of polarimetry on the ASDEX Upgrade DCN interferometer

Journal Article · Sat Nov 15 00:00:00 EST 2014 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4890574· OSTI ID:22303829

Casali, L.; Eixenberger, H. ^[1]; Ford, O. ^[2]

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1. Max-Planck-Institute for Plasma Physics, Garching 85748 (Germany)
2. Max-Planck-Institute for Plasma Physics, Greifswald 17491 (Germany)

The ASDEX Upgrade tokamak is equipped with a 5-channel DCN interferometer with a probing wavelength of 195 μm. Up to now, phase measurement and density calculation have been accomplished by hard-wired phase counting electronics. Meanwhile, a fast digitizer has been installed which acquires the raw signals. That way, the various causes of counting errors by integer multiples of 2π, so-called fringe jumps, can be analyzed, and phase reconstruction schemes based on digital signal processing can be developed. In addition, a prototype polarimeter setup has been installed on one channel and allows for measurement of the Faraday rotation experienced by the probing beam.

• OSTI ID: 22303829
• Journal Information: Review of Scientific Instruments, Vol. 85, Issue 11; Other Information: (c) 2014 Euratom; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ASDEX TOKAMAK
BEAMS
ERRORS
FARADAY EFFECT
INTERFEROMETERS
POLARIMETERS
POLARIMETRY
PROBES
WAVELENGTHS
WIRES