A wide angle view imaging diagnostic with all reflective, in-vessel optics at JET

Clever, M.; Arnoux, G.; Balshaw, N.; García-Sánchez, Pablo; Patel, Kunal; Sergienko, G.; Soler, D.; Stamp, M.; Williams, J.; Zastrow, K.‐D.

doi:10.1016/j.fusengdes.2013.01.038

Cited by 20 publications

(11 citation statements)

References 7 publications

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“…The camera system used here, called KLDT, is installed outside the JET biological shield and receives the image from an equatorial port after being transported along a path of more than 10 m. This complex design was done to allow camera operation at high neutron and gamma radiation levels as in the 2022 D-T campaign. The in-vessel optics image the JET vacuum chamber with a wide-angle view composed of two separate lines, a lower and an upper branch, each viewing one half of the machine [24]. Both are then combined to form a full intermediate image after the port window, which is finally transported via a mirror-based optical relay lens towards the camera system [25].…”

Section: Methodsmentioning

confidence: 99%

Measuring gross beryllium erosion with visible cameras in JET

Cal¹,

Losada²,

Balboa³

et al. 2022

Nucl. Fusion

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Two visible cameras with the same wide-angle view have been used to study the gross beryllium (Be) erosion in JET. An absolutely calibrated spectroscopy system employed in the past for the same object was used to quantitatively infer the camera photon fluxes and also to validate the results. To extract the effective sputtering yield, a simplified method is applied from the quotient of the measured radiances of the D α and the Be II line at 527 nm. The obtained results are in reasonably good agreement with those already published. The main benefit of using cameras is that the global view of the plasma–wall interaction surfaces of the whole vessel is monitored, and the different sources and their wetted areas can be identified and quantified. In addition, the measurement of the particle flux distributions can be used for the validation of three-dimensional erosion-transport codes.

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Section: Methodsmentioning

confidence: 99%

Measuring gross beryllium erosion with visible cameras in JET

Cal¹,

Losada²,

Balboa³

et al. 2022

Nucl. Fusion

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“…The IR cameras can measure the first wall and divertor temperature with a time resolution of 100 ms, a space resolution of the order of 7-10 mm, in the spectral range 3-5 μm. In the projects realized so far on the JET [50] and for the ITER [51], the optical design of the endoscope is usually quite delicate and involves many mirrors. The imaging properties of the first mirror (FM) will also depend on the capability of the in situ cleaning and surface protection of the FM using shutters.…”

Section: Diagnostics Important For the Demo Machine Protection Of Dif...mentioning

confidence: 99%

Diagnostics and control for the steady state and pulsed tokamak DEMO

Orsitto¹,

Villari²,

Moro³

et al. 2016

Nucl. Fusion

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The present paper is devoted to a first assessment of the DEMO diagnostics systems and controls in the context of pulsed and steady state reactor design under study in Europe. In particular, the main arguments treated are: (i) The quantities to be measured in DEMO and the requirements for the measurements; (ii) the present capability of the diagnostic and control technology, determining the most urgent gaps, and (iii) the program and strategy of the research and development (R&D) needed to fill the gaps. Burn control, magnetohydrodynamic stability, and basic machine protection require improvements to the ITER technology, and moderated efforts in R&D can be dedicated to infrared diagnostics (reflectometry, electron cyclotron emission, polarimetry) and neutron diagnostics. Metallic Hall sensors appear to be a promising candidate for magnetic measurements in the high neutron fluence and long/steady state discharges of DEMO.

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“…After the previous examples of tokamak tests of coated mirrors it was important to demonstrate a complete optical diagnostic system operating in a metallic tokamak and especially at JET. During the JET-ILW shutdown a wide angle camera system has been installed [39] in the horizontal mid-plane of the low field side with the field of view shown in the figure 6 of reference [39]. The 2011-2012 campaigns exposure lasted 18.9 h in total with approximately 13.1 h of X-point operation and after that the mirrors were exposed also to 19 h in total with 12 h of X-point operation for the 2013-2014 campaigns.…”

Section: Wide Angle Viewing System At Jet-ilwmentioning

confidence: 99%

“…The half images of the two branches are then combined on the camera sensor to form a full wide angle view image. The detailed description of the wide angle imaging system is given in [39]. A rhodium film (175 nm thick) was evaporated directly on polished flat stainless steel mirrors (60 40 mm).…”

Section: Wide Angle Viewing System At Jet-ilwmentioning

confidence: 99%

Optical Coatings as Mirrors for Optical Diagnostics

Marot

Arnoux

Huber

et al. 2016

J. Coat. Sci. Technol.

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The aim of this work was to provide a comprehensive insight concerning coated films which might be used for first mirrors in ITER. The influence of the mirror crystallite size has been addressed as well as the coating techniques to provide nanocrystalline films. Tests of coated mirrors both in laboratories and in tokamaks are reviewed. For the tokamak tests a wide angle camera system has been installed in JET-ILW which is composed of a mirror box with 3 stainless steel mirrors coated with rhodium viewing the torus through a conically shaped aperture. The system delivered the required image quality for plasma monitoring and wall protection. No or insignificant degradation of the optical transmittance has been observed during the experimental campaign in 2014 with about 3000 plasma pulses in different magnetic field configurations.

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A wide angle view imaging diagnostic with all reflective, in-vessel optics at JET

Cited by 20 publications

References 7 publications

Measuring gross beryllium erosion with visible cameras in JET

Measuring gross beryllium erosion with visible cameras in JET

Diagnostics and control for the steady state and pulsed tokamak DEMO

Optical Coatings as Mirrors for Optical Diagnostics

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