Relative frequency calibration for fast frequency sweep microwave reflectometry

Akira Ejiri; Yoshiyuki Shimada; Takuma Yamada; Takuya Oosako; Yuichi Takase; Hiroshi Kasahara

doi:10.1585/pfr.2.040

Relative frequency calibration for fast frequency sweep microwave reflectometry

Akira Ejiri, Yoshiyuki Shimada, Takuma Yamada, Takuya Oosako, Yuichi Takase, Hiroshi Kasahara

Division for Experimental Natural Science

Research output: Contribution to journal › Article › peer-review

4 Citations (Scopus)

Abstract

A frequency-modulated reflectometer with a frequency band of 26.5 to 40GHz has been constructed and installed in the TST-2 spherical tokamak to measure fast density profile evolution. In order to calibrate the instantaneous frequency for various frequency sweep rates, a waveform matching method has been proposed and applied to the reflectometer. This method compares the interference patterns (i.e., waveforms) of a fixed target reflection, which do not depend on the sweep rate, and obtains the instantaneous frequency by fitting the target waveform time to the time for a reference sweep waveform. This allows evaluation of output frequency stability. The overall frequency error, including reproducibility, is around 0.1 GHz. Sweep rates up to 20 μs were used to measure the density profile evolution during rf heating.

Original language	English
Article number	040
Journal	Plasma and Fusion Research
Volume	2
DOIs	https://doi.org/10.1585/pfr.2.040
Publication status	Published - 2007

All Science Journal Classification (ASJC) codes

Condensed Matter Physics

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10.1585/pfr.2.040

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title = "Relative frequency calibration for fast frequency sweep microwave reflectometry",

abstract = "A frequency-modulated reflectometer with a frequency band of 26.5 to 40GHz has been constructed and installed in the TST-2 spherical tokamak to measure fast density profile evolution. In order to calibrate the instantaneous frequency for various frequency sweep rates, a waveform matching method has been proposed and applied to the reflectometer. This method compares the interference patterns (i.e., waveforms) of a fixed target reflection, which do not depend on the sweep rate, and obtains the instantaneous frequency by fitting the target waveform time to the time for a reference sweep waveform. This allows evaluation of output frequency stability. The overall frequency error, including reproducibility, is around 0.1 GHz. Sweep rates up to 20 μs were used to measure the density profile evolution during rf heating.",

author = "Akira Ejiri and Yoshiyuki Shimada and Takuma Yamada and Takuya Oosako and Yuichi Takase and Hiroshi Kasahara",

note = "Funding Information: We are grateful for experimental contributions by the TST-2 Team. This work was supported by JSPS under Grant-in-Aid for Scientific Research Nos. 17044002 and 16106013. Publisher Copyright: {\textcopyright} 2007 The Japan Society of Plasma Science and Nuclear Fusion Research.",

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doi = "10.1585/pfr.2.040",

language = "English",

volume = "2",

journal = "Plasma and Fusion Research",

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publisher = "The Japan Society of Plasma Science and Nuclear Fusion Research (JSPF)",

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T1 - Relative frequency calibration for fast frequency sweep microwave reflectometry

AU - Ejiri, Akira

AU - Shimada, Yoshiyuki

AU - Yamada, Takuma

AU - Oosako, Takuya

AU - Takase, Yuichi

AU - Kasahara, Hiroshi

N1 - Funding Information: We are grateful for experimental contributions by the TST-2 Team. This work was supported by JSPS under Grant-in-Aid for Scientific Research Nos. 17044002 and 16106013. Publisher Copyright: © 2007 The Japan Society of Plasma Science and Nuclear Fusion Research.

PY - 2007

Y1 - 2007

N2 - A frequency-modulated reflectometer with a frequency band of 26.5 to 40GHz has been constructed and installed in the TST-2 spherical tokamak to measure fast density profile evolution. In order to calibrate the instantaneous frequency for various frequency sweep rates, a waveform matching method has been proposed and applied to the reflectometer. This method compares the interference patterns (i.e., waveforms) of a fixed target reflection, which do not depend on the sweep rate, and obtains the instantaneous frequency by fitting the target waveform time to the time for a reference sweep waveform. This allows evaluation of output frequency stability. The overall frequency error, including reproducibility, is around 0.1 GHz. Sweep rates up to 20 μs were used to measure the density profile evolution during rf heating.

AB - A frequency-modulated reflectometer with a frequency band of 26.5 to 40GHz has been constructed and installed in the TST-2 spherical tokamak to measure fast density profile evolution. In order to calibrate the instantaneous frequency for various frequency sweep rates, a waveform matching method has been proposed and applied to the reflectometer. This method compares the interference patterns (i.e., waveforms) of a fixed target reflection, which do not depend on the sweep rate, and obtains the instantaneous frequency by fitting the target waveform time to the time for a reference sweep waveform. This allows evaluation of output frequency stability. The overall frequency error, including reproducibility, is around 0.1 GHz. Sweep rates up to 20 μs were used to measure the density profile evolution during rf heating.

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JF - Plasma and Fusion Research

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Relative frequency calibration for fast frequency sweep microwave reflectometry

Abstract

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