Impact of reflections on the divertor and first wall temperature measurements from the ITER infrared imaging system

Aumeunier, M.-H.; Kočan, M.; Reichle, R.; Gauthier, E.

doi:10.1016/j.nme.2017.02.014

Cited by 30 publications

(17 citation statements)

References 13 publications

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“…It is also worth mentioning that for low emissivity values, the reflected fluxes can significantly contribute to the collected signal by the IR system and this has to be considered in the IR monitoring system. As a consequence, with the introduction of all-metal walls in fusion devices [9,10], surface emissivity becomes a very important and challenging issue for accurate surface temperature measurement [11,12].…”

Section: Introductionmentioning

confidence: 99%

Emissivity measurement of tungsten plasma facing components of the WEST tokamak

Gaspar

Pocheau

Corre

et al. 2019

Fusion Engineering and Design

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Since tungsten (W) has been selected as material for the ITER divertor target the knowledge of the emissivity in the infrared (IR) wavelength range becomes mandatory. A dedicated setup has been developed to measure the emissivity in the wavelength range 1.7-4.75 µm and the temperature domain 200-850 °C. The paper presents the emissivity measurements on W samples coming from actively cooled bulk W components (ITER-like) and W-coated graphite component of the WEST divertor. W samples with damaged surfaces generated by transient heat load as those observed in fusion machines, including micro-cracks and crack network, are also investigated. The dependence on wavelength, temperature and surface state are shown and discussed.

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Section: Introductionmentioning

confidence: 99%

Emissivity measurement of tungsten plasma facing components of the WEST tokamak

Gaspar

Pocheau

Corre

et al. 2019

Fusion Engineering and Design

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“…The first is a wide range RGA used to follow species of a mass up to 46 m/q. The second is a high resolution 0-6 m/q RGA 4 He and 9 Be( 3 He, p) 11 B nuclear reactions. A 3 He probing ion beam with the energy of 2.0 MeV and 0.8 MeV was used and the number of reaction protons with respect to their energy was measured.…”

Section: Methodsmentioning

confidence: 99%

“…Moreover, the WallDYN [2] code for impurity migration and wall composition dynamics was used to predict Be deposition patterns and the resulting co-deposition for ITER [3]. The calculation predicts significant Be deposition on inner and outer divertor baffles, where the predicted surface temperature is around 388 K [4], according to calculations performed with SOLPS 4.3 code package [5]. However, extrapolation from JET-ILW to ITER is not straigthforward and simulation results depend strongly on the assumptions of ITER design and operation conditions.…”

Section: Introductionmentioning

confidence: 99%

The influence of helium on deuterium retention in beryllium co-deposits

Založnik¹,

Baldwin²,

Doerner³

et al. 2018

Journal of Nuclear Materials

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Tritium co-deposition with materials from the plasma-facing components is expected to be the main contributor to tritium retention in ITER. Since He will also be present in the plasma as fusion ash during the DT campaign, this study focuses on the effect of He on D retention in Be co-deposits. The PISCES-B linear plasma device was used to create co-deposited BeD He layers for various deposition temperatures (295 K-475 K) and He concentrations in D − αHe plasma mixtures (0 ≤ α ≤ 0.1). Thermal desorption spectroscopy and nuclear reaction analysis were used to determine the D concentration in co-deposits. For the lowest He concentration (1%) an increase of D retention was observed for the deposition at room temperature, whereas for higher He concentrations a declining trend of D retention was found. Including 10% of He in the plasma is found to reduce D retention at deposition temperatures below 425 K and have a negligible effect at higher deposition temperatures.

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“…For post pulse analysis, emissivity < 1 can be applied on the IR data. Pre and post pulse analysis tools and detailed simulations are developed in parallel to better analyse and understand the impact of variable emissivity and reflections on measured temperature [8,9].…”

Section: Temperature Monitoringmentioning

confidence: 99%

Full coverage infrared thermography diagnostic for WEST machine protection

Courtois

Aumeunier

Balorin

et al. 2019

Fusion Engineering and Design

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The WEST platform aims at testing ITER like W divertor targets in an integrated tokamak environment. To operate long plasma discharges, IR thermography is required to monitor the main plasma facing components by means of real time surface temperature measurements, while providing essential data for various physics studies. To monitor the new divertor targets, the WEST IR thermography protection system has been deeply renewed, to match the new tokamak configuration. It consists of 7 endoscopes located in upper ports viewing the whole lower divertor and the 5 heating devices. Electronic devices and computers allow data storage of ≈3 Gb/s IR images and real time video frames processing at 50 Hz rate, to ensure the protection of the main plasma facing components during plasma discharges by a feedback control of the power injected by the heating systems. Each endoscope provides 2 views covering 2 divertor sectors of 30°(toroidally) and 1 view of a heating antenna. Each optical line is composed of a tight entrance window followed by a head objective which forms an image transported through the endoscope by a series of 4 optical relays and mirrors, up to a camera objective. Finally, 12 IR cameras specially developed for WEST environment capture the thermographic data, at the wavelength of 3.9 μm, with a 640 × 512 pixels frame size. The paper describes the design constraints and diagnostic technologies: optics, mechanics, electronics, hard & software, cameras. Tvhe laboratory characterization procedures (Modulation Transfer Function, slit response, calibration), and the measurement performance results are given (spatial resolution, temperature threshold). Finally, first results obtained during experimental campaigns in WEST are presented.

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Impact of reflections on the divertor and first wall temperature measurements from the ITER infrared imaging system

Cited by 30 publications

References 13 publications

Emissivity measurement of tungsten plasma facing components of the WEST tokamak

Emissivity measurement of tungsten plasma facing components of the WEST tokamak

The influence of helium on deuterium retention in beryllium co-deposits

Full coverage infrared thermography diagnostic for WEST machine protection

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