Design of a digital multiradian phase detector and its application in fusion plasma interferometry

A. Mlynek, E. Vainonen-Ahlgren, ASDEX Upgrade Team

Research output: Contribution to journalArticleScientificpeer-review

31 Citations (Scopus)

Abstract

We discuss the circuit design of a digital multiradian phase detector that measures the phase difference between two 10 kHz square wave TTL signals and provides the result as a binary number. The phase resolution of the circuit is 1/64 period and its dynamic range is 256 periods. This circuit has been developed for fusion plasma interferometry with submillimeter waves on the ASDEX Upgrade tokamak. The results from interferometric density measurement are discussed and compared to those obtained with the previously used phase detectors, especially with respect to the occurrence of phase jumps. It is illustrated that the new phase measurement provides a powerful tool for automatic real-time validation of the measured density, which is important for feedback algorithms that are sensitive to spurious density signals.
Original languageEnglish
Article number033507
JournalReview of Scientific Instruments
Volume81
DOIs
Publication statusPublished - 2010
MoE publication typeA1 Journal article-refereed

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phase detectors
Interferometry
interferometry
Fusion reactions
fusion
Detectors
Plasmas
Networks (circuits)
Transistor transistor logic circuits
Submillimeter waves
Phase measurement
submillimeter waves
square waves
dynamic range
occurrences
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Cite this

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abstract = "We discuss the circuit design of a digital multiradian phase detector that measures the phase difference between two 10 kHz square wave TTL signals and provides the result as a binary number. The phase resolution of the circuit is 1/64 period and its dynamic range is 256 periods. This circuit has been developed for fusion plasma interferometry with submillimeter waves on the ASDEX Upgrade tokamak. The results from interferometric density measurement are discussed and compared to those obtained with the previously used phase detectors, especially with respect to the occurrence of phase jumps. It is illustrated that the new phase measurement provides a powerful tool for automatic real-time validation of the measured density, which is important for feedback algorithms that are sensitive to spurious density signals.",
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Design of a digital multiradian phase detector and its application in fusion plasma interferometry. / Mlynek, A.; Vainonen-Ahlgren, E.; ASDEX Upgrade Team.

In: Review of Scientific Instruments, Vol. 81, 033507, 2010.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Design of a digital multiradian phase detector and its application in fusion plasma interferometry

AU - Mlynek, A.

AU - Vainonen-Ahlgren, E.

AU - ASDEX Upgrade Team

PY - 2010

Y1 - 2010

N2 - We discuss the circuit design of a digital multiradian phase detector that measures the phase difference between two 10 kHz square wave TTL signals and provides the result as a binary number. The phase resolution of the circuit is 1/64 period and its dynamic range is 256 periods. This circuit has been developed for fusion plasma interferometry with submillimeter waves on the ASDEX Upgrade tokamak. The results from interferometric density measurement are discussed and compared to those obtained with the previously used phase detectors, especially with respect to the occurrence of phase jumps. It is illustrated that the new phase measurement provides a powerful tool for automatic real-time validation of the measured density, which is important for feedback algorithms that are sensitive to spurious density signals.

AB - We discuss the circuit design of a digital multiradian phase detector that measures the phase difference between two 10 kHz square wave TTL signals and provides the result as a binary number. The phase resolution of the circuit is 1/64 period and its dynamic range is 256 periods. This circuit has been developed for fusion plasma interferometry with submillimeter waves on the ASDEX Upgrade tokamak. The results from interferometric density measurement are discussed and compared to those obtained with the previously used phase detectors, especially with respect to the occurrence of phase jumps. It is illustrated that the new phase measurement provides a powerful tool for automatic real-time validation of the measured density, which is important for feedback algorithms that are sensitive to spurious density signals.

U2 - 10.1063/1.3340944

DO - 10.1063/1.3340944

M3 - Article

VL - 81

JO - Review of Scientific Instruments

JF - Review of Scientific Instruments

SN - 0034-6748

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