Real-time protection of the JET ITER-like wall based on near infrared imaging diagnostic systems

Huber, A.; Kinna, D.; Huber, V.; Arnoux, G.; Sergienko, G.; Balboa, I.; Balorin, C.; Carman, P.; Carvalho, P.; Collins, S.; Conway, N. J.; McCullen, P.; Drenik, A.; Jachmich, S.; Jouve, M.; Linsmeier, Ch.; Lomanowski, B.; Lomas, P. J.; Lowry, C.; Maggi, C. F.; Matthews, G. F.; Meigs, A.; Mertens, Ph.; Nunes, I.; Price, M.; Puglia, P.; Riccardo, V.; Rimini, F.; Widdowson, A.; Zastrow, K.‐D.; Contributors, Jet

doi:10.1088/1741-4326/aad481

Cited by 16 publications

(21 citation statements)

References 53 publications

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“…HUBER 1 , A. HUBER 2 , D. KINNA 3 , G.F. MATTHEWS 3 , G. SERGIENKO 2 , I. BALBOA 3 , S. BREZINSEK 2 , P. J. LOMAS 3 , J. MAILLOUX 3 , P. MCCULLEN 3 , PH. MERTENS 2 , F. G. RIMINI 3 , K-D. ZASTROW 3 and JET CONTRIBUTERS * Email: V.Huber@fz-juelich.de [1] Forschungszentrum Jülich GmbH, Supercomputing Centre, Jülich, Germany [2] Forschungszentrum Jülich GmbH, Institut für Energie-und Klimaforschung -Plasmaphysik, Jülich, Germany…”

Section: The Software and Hardware Architecture Of The Real-time Protection Of In-vessel Components In Jet-ilwunclassified

“…The JET-ILW imaging system for machine protection [3] is based on analogue monochrome CCD cameras (Hitachi KP-M1AP; sensor: Sony ICX423AL, Sensor size 768x576, pixel size: 11.6 μm (H)×11.2 μm (V)), equipped with Near InfraRed (NIR) filters operating in the near infrared spectral region (970nm-1300nm). Synchronized with the external sync signals (V/H scans), the cameras operate in non-interlaced mode at 50 fields per second with binning (odd and even lines are exposed together at the same time).…”

Section: Near Infrared Imaging Diagnostic Systemsmentioning

confidence: 99%

“…which should not contribute to the calculation because they are caused by sensor aberrations or transient phenomena such as neutron hits, and its implementation, are described in [3]. The overall system, from the ROIs to the responses, is highly configurable.…”

Section: Fig1 Video Digitization and Distributionmentioning

confidence: 99%

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The software and hardware architecture of the real-time protection of in-vessel components in JET-ILW

Huber

Kinna

et al. 2019

Nucl. Fusion

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For the first time, the JET operation in deuterium-tritium (D-T) plasma, which is scheduled to take place on JET in 2020, will be performed in the ITER mix of plasma-facing component materials. In view of the preparation of the DT campaign (DTE2), several aspects of the plasma operation require significant improvements, such as a real-time protection of the first wall. The risk of damaging the metallic PFCs caused by beryllium melting or cracking of tungsten owing to thermal fatigue required a new reliable D-T compatible active protection system. Therefore, the future development of the JET real time first wall protection is focused on the D-T campaign and the ITER relevant conditions which may cause failure of camera electronics within the Torus hall. In addition to the technological aspect, the intensive preparation of the diverse software tools and real time algorithms for hot spot detection as well as alarm handling strategy required for the wall protection is in progress.This contribution describes the improved design, implementation, and operation of the near infrared (NIR) imaging diagnostic system of the JET-ILW plasma experiment and its integration into the existing JET protection architecture. To provide the reliable wall protection during the DTE2, two more sensitive logarithmic NIR camera systems equipped with new optical relays to take images and cameras outside of the biological shield have been installed on JET-ILW and calibrated with an in-vessel calibration light source (ICLS). Additionally, post-pulse data visualization and advanced analysis of all types of imaging data is provided by the new software framework JUVIL (JET users video imaging library). The formation of hot spots is recognized as a significant threat due to rapid surface temperature rise. Because it could trigger the protection system to stop a pulse, it is important to identify the mechanisms and conditions responsible for the formation of such hot spots. To address this issue the new software tool 'Hotspot Editor' has been developed.

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Section: The Software and Hardware Architecture Of The Real-time Protection Of In-vessel Components In Jet-ilwunclassified

Section: Near Infrared Imaging Diagnostic Systemsmentioning

confidence: 99%

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The software and hardware architecture of the real-time protection of in-vessel components in JET-ILW

Huber

Kinna

et al. 2019

Nucl. Fusion

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“…These are the Langmuir probe tips, seen along a straight line across tile 5, and the exposed tungsten lamella on the inboard side of tile 5, which was deliberately melted in a dedicated experiment [16,17]. The number of detected Langmuir probe tips is reduced considerably at the highest threshold value, but the exposed lamella persists all throughout the range as the surface was at the melting point of tungsten whereas the signal of the protection camera saturates at lower surface temperatures [8]. It can be also noted that, apart from the deliberately exposed surfaces, very little hot spots were detected on the surface of tile 5, which is not surprising as the surfaces of bulk-W tiles are expected to be more resilient than W-coating on CFC tiles, and for geometrical reasons, accumulation of debris is not expected to be the most prominent in this part of the divertor [18].…”

Section: Analysis Of the Hot Spot Activitymentioning

confidence: 99%

“…In order to prevent recrystallization of the bulk W tile, and the delamination of the W coatings, the surface temperature must be kept below 1200 °C [3,4]. To prevent such damage to the plasma facing components (PFCs) due to excessive heat loads, JET relies on an array of video cameras, protection cameras, which monitor the temperature of the plasma facing surfaces [5][6][7][8]. The field of view of each protection camera is split into pre-determined regions of interest (ROIs).…”

Section: Introductionmentioning

confidence: 99%

Analysis of the outer divertor hot spot activity in the protection video camera recordings at JET

Drenik

Brezinsek

Carvalho

et al. 2019

Fusion Engineering and Design

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Hot spots on the divertor tiles at JET result in overestimation of the tile surface temperature which causes unnecessary termination of pulses. However, the appearance of hot spots can also indicate the condition of the divertor tile surfaces. To analyse the behaviour of the hot spots in the outer divertor tiles of JET, a simple image processing algorithm is developed. The algorithm isolates areas of bright pixels in the camera image and compares them to previously identified hot spots. The activity of the hot spots is then linked to values of other signals and parameters in the same time intervals. The operation of the detection algorithm was studied in a limited pulse range with high hot spot activity on the divertor tiles 5, 6 and 7. This allowed us to optimise the values of the controlling parameters. Then, the wider applicability of the method has been demonstrated by the analysis of the hot spot behaviour in a whole experimental campaign.

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Optical Noninvasive Temperature Measurement of Molten Melts in Metallurgical Process: A Review

Liu

et al. 2022

MAPAN

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Real-time protection of the JET ITER-like wall based on near infrared imaging diagnostic systems

Cited by 16 publications

References 53 publications

The software and hardware architecture of the real-time protection of in-vessel components in JET-ILW

The software and hardware architecture of the real-time protection of in-vessel components in JET-ILW

Analysis of the outer divertor hot spot activity in the protection video camera recordings at JET

Optical Noninvasive Temperature Measurement of Molten Melts in Metallurgical Process: A Review

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