A simple frequency sweep linearization method for FM density profile reflectometry

POSTER

Abstract

Frequency modulated, continuous wave (FMCW) reflectometry is widely used to measure the electron density profile on fusion devices. To ensure the output intermediate frequency signal is proportional to the propagation delay time, the frequency sweep should be linearized, especially for reflectometry with sweeping periods of only a few microseconds. We introduce a simple dynamic calibration technique to linearize the frequency sweep based on digital complex demodulation methods, without using a Fourier transform, which would induce a trade-off between frequency and time resolution. The technique is convenient as it can be done in the same conditions as for plasma measurements. The method is in use on the EAST profile reflectometer, and results will be presented.\\[4pt] Work was supported by the Natural Science Foundation of China (NSFC) under 11475173, National Magnetic Confinement Fusion Energy Development Program of China under 2013GB106002 and 2014GB109002, and US DOE Grants DE- SC0010424 and DE-SC0010469.

Authors

  • Adi Liu

    • University of Science and Technology of China

  • Jianqiang Hu

    • University of Science and Technology of China

  • E.J. Doyle

    • University of California, Los Angeles
    • UCLA

  • Jin Zhang

    • University of Science and Technology of China

  • Hong Li

    • University of Science and Technology of China

  • Chu Zhou

    • University of Science and Technology of China

  • Xiaohui Zhang

    • University of Science and Technology of China

  • Mingyuan Wang

    • University of Science and Technology of China

  • Tao Lan

    • University of Science and Technology of China

  • Jinglin Xie

    • University of Science and Technology of China

  • Wandong Liu

    • University of Science and Technology of China

  • Changxuan Yu

    • University of Science and Technology of China