Routine studies are performed on JET using a new set of antennas to excite Toroidal Alfvén Eigenmodes (TAE). A TAE resonance footprint is observed in the plasma response measurement when there is a noticeable variation in both the amplitude and the phase of the response with respect to the excitation. An algorithm for real-time identification of TAE resonances, based on a hardware lock-in amplifier, is presently used at the Joint European Torus (JET) tokamak for detecting such variations. In this paper, we revisit the problem of estimating the I-Q characteristics from a known non-stationary frequency mode, with a resonant-like phase response, embedded in a digital signal. A non-stationary linear model is used in a recursive filter implementation of a lock-in amplifier. We propose it as a viable alternative to hardware synchronous detectors such as the one in use at the JET and compare its' performance with standard digital lock-in techniques in terms of bandwidth and phase response under high throughput rates requirements. © 2010 IEEE.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Nuclear Energy and Engineering
- Electrical and Electronic Engineering
Alves, D., Coelho, R., Klein, A., Panis, T., & Murari, A. (2010). A real-time synchronous detector for the TAE antenna diagnostic at JET. IEEE Transactions on Nuclear Science, 57(2 PART 1), 577 - 582. . https://doi.org/10.1109/TNS.2009.2033679