Recovery of electron density signals beyond the operating range of the measuring instrument

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Abstract

Machine learning models have been widely incorparated into control systems aimed at improving the operational efficiency of tokamaks. The training machine learning models requires substantial datasets. However, data collection is limited because experimental campaigns on tokamaks are prolonged in time. Furthermore, the amount of suitable training data may decrease due to the present of faulty diagnostic signals. Additionally, the frequency of faulty signal occurrences increases while initial operation of a new tokamak or specialized equipment. This work examines the possibility of recovering faulty signals using machine learning techniques. Particularly, we focus on recovering signals obtained beyond the operating range of measuring instruments. Thus, recovering such kind of signals should increase the volume of available training data, consequently enhancing the efficacy of machine learning-based model training.

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About the authors

Nikolai V. Leshov

Moscow Technical University of Communications and Informatics (MTUCI); State Research Centre of the Russian Federation Troitsk Institute for Innovation and Fusion Research

Author for correspondence.
Email: nikolya.leshov@gmail.com
ORCID iD: 0000-0002-7844-1768

postgraduate student, Department of Mathematical Cybernetics and Information Technologies

Russian Federation, Moscow; Troitsk, Moscow

Anastasia N. Shcherbak

State Research Centre of the Russian Federation Troitsk Institute for Innovation and Fusion Research

Email: shcherbak@triniti.ru
ORCID iD: 0000-0002-0942-9837

leading engineer, Laboratory of Tokamak Plasma Diagnostics and Plasma Physics, Department of Tokamak and Current-Carrying Plasma Physics

Russian Federation, Troitsk, Moscow

Mikhail G. Gorodnichev

Moscow Technical University of Communications and Informatics (MTUCI)

Email: m.g.gorodnichev@mtuci.ru
ORCID iD: 0000-0003-1739-9831

Cand. Sci. (Eng.), Associate Professor, Dean, Faculty “Information Technology”

Russian Federation, Moscow

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Supplementary files

Supplementary Files
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1. JATS XML
2. Fig. 1. Correct signal

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3. Fig. 2. Signal beyond operating range

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4. Fig. 3. Transformed signal beyond operating range

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5. Fig. 4. Distribution by duration of the “gap”

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6. Fig. 5. Synthetic signal

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7. Fig. 6. Distribution of signals beyond operating range in space

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8. Fig. 7. Distribution of correct signals in space

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9. Fig. 8. Model architecture

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10. Fig. 9. Learning curve

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11. Fig. 10. Recovered synthetic signal

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12. Fig. 11. Recovered signal and original signal

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