M. Szutyányi

57193684506

Publications - 3

Characterization of edge and scrape-off layer fluctuations using the fast Li-BES system on COMPASS

Publication Name: Plasma Physics and Controlled Fusion

Publication Date: 2019-06-21

Volume: 61

Issue: 8

Page Range: Unknown

Description:

Recently the Lithium-Beam Emission Spectroscopy (Li-BES) system on COMPASS has reached its full diagnostic power in terms of routine automatic operation in any kind of plasma scenarios and it is normally used as a standard tool for reconstruction of ultra fast density profiles in the edge region of COMPASS plasmas. The purpose of this study is to investigate the advantages and limitations of the COMPASS Li-BES system in characterizing plasma electron density fluctuations. We show how the atomic physics of plasma-beam interactions can affect the interpretation of the measurement at different radial positions and for different electron density profiles. We also demonstrate the usability of generalized sequential probability ratio test for automatic event detection. Using non-perturbative diagnostic, we verify the validity of the stochastic Garcia-model for scrape-off layer filaments and accompanying holes (density deficits).

Open Access: Yes

DOI: 10.1088/1361-6587/ab24a0

Automatic ELM detection and study of statistical ELM properties by Li-BES on COMPASS

Publication Name: 46th Eps Conference on Plasma Physics Eps 2019

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

No description provided

Open Access: Yes

DOI: DOI not available

Automatic ELM detection using gSPRT on the COMPASS tokamak

Publication Name: Fusion Engineering and Design

Publication Date: 2017-11-01

Volume: 123

Issue: Unknown

Page Range: 950-954

Description:

This paper contains the description of the generalized Sequential Probability Ratio Test (gSPRT) method used for automatic ELM detection in different diagnostic signals collected on the COMPASS tokamak. After determination of H-mode region based on Dα signal in a given shot, ELMs are automatically detected in different diagnostic time traces (e.g. magnetic signals and also in Dα signals). The onset time, the maximum location and the peak value, and the duration of each detected ELM is determined. Analyzed diagnostic signals came from different radial positions of the studied plasma volume, thus from arrival times of given ELM into different detectors, the average radial propagation velocity of the ELM event can be also estimated. Comparison of results from gSPRT method with two different, commonly used automatic ELM detection method (threshold technique and correlation based technique) is also reported.

Open Access: Yes

DOI: 10.1016/j.fusengdes.2017.03.025