Design of the ITER VUV edge imaging spectrometer and R&amp;D for the rotary motional vacuum feed-through

Seon, C. R.; Jeon, Je-Eon; Cheon, MunSeong; Pak, S.; Lee, H.G.; Bernascolle, Philippe; Barnsley, R.

doi:10.1016/j.fusengdes.2016.02.025

Cited by 9 publications

(8 citation statements)

References 7 publications

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“…Whereas radiation induced luminescence mainly affects those diagnostics with very weak signals, radiation induced attenuation affects all diagnostics using refractive optics and optical fibres. Even for radiation hardened optical fibres an attenuation of several dB/m can be expected at the end of ITER life in the interspace [13] (see figure 5). Measures such as providing extra shielding around optical fibres, providing heating for annealing the radiation damage and foreseeing the possibility of periodic replacement of the fibres in the interspace are to be taken into account in the design of spectroscopy diagnostics that plan on using optical fibres.…”

Section: Effects Of Radiation On Optical and Electronic Componentsmentioning

confidence: 99%

ITER perspective on fusion reactor diagnostics—A spectroscopic view

et al. 2016

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Section: Effects Of Radiation On Optical and Electronic Componentsmentioning

confidence: 99%

ITER perspective on fusion reactor diagnostics—A spectroscopic view

et al. 2016

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“…In KSTAR, several imaging diagnostics with tomographic reconstruction algorithms have been developed for impurity transport study [8][9][10][11], including the tungsten powder injection experiment. However, both the vacuum (VUV) and extreme ultraviolet (EUV) spectrometers [10,12] on KSTAR and the one planned for ITER [13], which have a capability of resolving the spatial distribution of line emissions, suffer from a limited viewing angle due to the narrow allocated space, which makes it difficult to accurately reconstruct the local emissivity profile of each line radiation from the chordintegrated data. The ITER VUV spectrometers are expected to employ 5 channels having different fields of view (FoVs) with different wavelengths [12][13][14].…”

Section: Local Profiles Of Line Emission Of Impurity Ions In Rotating...mentioning

confidence: 99%

“…However, both the vacuum (VUV) and extreme ultraviolet (EUV) spectrometers [10,12] on KSTAR and the one planned for ITER [13], which have a capability of resolving the spatial distribution of line emissions, suffer from a limited viewing angle due to the narrow allocated space, which makes it difficult to accurately reconstruct the local emissivity profile of each line radiation from the chordintegrated data. The ITER VUV spectrometers are expected to employ 5 channels having different fields of view (FoVs) with different wavelengths [12][13][14]. Therefore, inadequate lines of sight (LoSs) may lead to the inaccurate local profiles by using the conventional tomographic methods.…”

Section: Local Profiles Of Line Emission Of Impurity Ions In Rotating...mentioning

confidence: 99%

Local profiles of line emission of impurity ions in rotating fusion plasmas

2020

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We analyze the poloidal distribution of impurity ions, such as C V, C VI and O VIII, in fast rotating KSTAR plasmas using the impurity emission lines in the 1–7 nm wavelength range obtained from the space-resolved extreme ultra violet spectrometer. This is aided particularly by a new tomographic reconstruction technique with limited viewing angles. The vacuum and extreme ultraviolet spectrometer system at ITER and its prototypes installed at KSTAR are one of the main diagnostic systems to monitor the impurity species in fusion plasmas; however, they have an insufficient field of view to utilize the conventional reconstruction method. The new algorithm developed in this work considers a curvilinear grid of pixels mapped onto the magnetic equilibrium and a weight factor considering toroidal rotational effect on impurity species. Validation tests with poloidally asymmetric images of synthetic plasma demonstrate that this method is highly useful for emission diagnostics that have a narrow field of view. The experimental results of the spatially resolved spectra from KSTAR plasma clearly show that even the light impurities such as carbon and oxygen are significantly affected by the toroidal rotation. Accordingly, the method is expected to be utilized for estimating the poloidal density profile of each charge state of an impurity species, which will play a key role in impurity transport studies.

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“…The VUV edge imaging spectrometer in upper port #18 consists of one field mirror with cylindrical geometry, one collimating mirror with ellipsoidal geometry, and a VUV imaging spectrometer. 12 The equatorial system in equatorial port #11 employs a VUV survey spectrometer with five channels for wideband coverage and having high spectral and time resolution. The divertor VUV spectrometer is also located at equatorial port #11 with relay optics consisting of a field mirror and a collimating mirror.…”

Section: Iter Vuv Core Survey Spectrometermentioning

confidence: 99%

VUV spectroscopy in impurity injection experiments at KSTAR using prototype ITER VUV spectrometer

Seon

Hong

Song

et al. 2017

Review of Scientific Instruments

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The ITER vacuum ultra-violet (VUV) core survey spectrometer has been designed as a 5-channel spectral system so that the high spectral resolving power of 200-500 could be achieved in the wavelength range of 2.4-160 nm. To verify the design of the ITER VUV core survey spectrometer, a two-channel prototype spectrometer was developed. As a subsequent step of the prototype test, the prototype VUV spectrometer has been operated at KSTAR since the 2012 experimental campaign. From impurity injection experiments in the years 2015 and 2016, strong emission lines, such as Kr xxv 15.8 nm, Kr xxvi 17.9 nm, Ne vii 46.5 nm, Ne vi 40.2 nm, and an array of largely unresolved tungsten lines (14-32 nm) could be measured successfully, showing the typical photon number of 10-10 photons/cm s.

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Design of the ITER VUV edge imaging spectrometer and R&D for the rotary motional vacuum feed-through

Cited by 9 publications

References 7 publications

ITER perspective on fusion reactor diagnostics—A spectroscopic view

ITER perspective on fusion reactor diagnostics—A spectroscopic view

Local profiles of line emission of impurity ions in rotating fusion plasmas

VUV spectroscopy in impurity injection experiments at KSTAR using prototype ITER VUV spectrometer

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