Status of the R&amp;D activities to the design of an ITER core CXRS diagnostic system

Mertens, Philippe; Bardawil, D.A. Castaño; Baross, T.; Biel, W.; Friese, Sebastian; Hawkes, N.; Jaspers, R.; Kotov, V.; Krasikov, Yu.; Krimmer, A.; Litnovsky, A.; Marchuk, O.; Neubauer, O.; Offermanns, Guido; Panin, A.; Pokol, Gergö; Schrader, M.; Samm, U.

doi:10.1016/j.fusengdes.2015.05.039

Cited by 10 publications

(3 citation statements)

References 28 publications

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“…By designing the duct leading to the first mirror in a clever way one can either trap or redirect the incoming particle flux. For the main plasma chamber, where the particle flux is expected to be non-collisional, a design with fins or baffles, as shown in figure 1 (left) and [2], is envisaged. In the divertor region, however, a pressure driven fluid-like flow can be expected during ELMs, which can be mitigated by shaping of the duct and adding an expansion chamber.…”

Section: • Active Shutters • Appropriate Mirror Materialsmentioning

confidence: 99%

ITER perspective on fusion reactor diagnostics—A spectroscopic view

et al. 2016

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Section: • Active Shutters • Appropriate Mirror Materialsmentioning

confidence: 99%

ITER perspective on fusion reactor diagnostics—A spectroscopic view

et al. 2016

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“…mainly beryllium (Be) and tungsten (W) [1,2]. Along with laser cleaning [3][4][5][6] in situ plasma sputtering is currently considered as one of the most promising cleaning techniques to remove deposits from FMs [7,8]. For the latter, several studies conducted worldwide have shown successful plasma cleaning on molybdenum (Mo) or stainless steel mirrors (up to a size of 90 mm diameter) contaminated with aluminium (Al), alumina (Al 2 O 3 ), W or mixture of them [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Plasma cleaning of beryllium coated mirrors

et al. 2016

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Cleaning systems of metallic first mirrors are needed in more than 20 optical diagnostic systems from ITER to avoid reflectivity losses. Currently, plasma sputtering is considered as one of the most promising techniques to remove deposits coming from the main wall (mainly beryllium and tungsten). This work presents the results of plasma cleaning of rhodium and molybdenum mirrors exposed in JET-ILW and contaminated with typical tokamak elements (including beryllium and tungsten). Using radio frequency (13.56 MHz) argon or helium plasma, the removal of mixed layers was demonstrated and mirror reflectivity improved towards initial values. The cleaning was evaluated by performing reflectivity measurements, Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy and ion beam analysis.

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“…Rhodium has also a low chemical reactivity, preventing oxide and carbide formation [12,13]. Due to the aforementioned optical and chemical properties, rhodium is considered to be an important candidate material for first mirrors in ITER [14][15][16]. The mirrors of the ex-vessel optics of both imaging systems are made of aluminium to cover the spectral range up to 2500 nm.…”

Section: Near-infrared Swir Logarithmic Imaging Diagnostics Systemsmentioning

confidence: 99%

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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Status of the R&D activities to the design of an ITER core CXRS diagnostic system

Cited by 10 publications

References 28 publications

ITER perspective on fusion reactor diagnostics—A spectroscopic view

ITER perspective on fusion reactor diagnostics—A spectroscopic view

Plasma cleaning of beryllium coated mirrors

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

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