Progress in Development of Edge Thomson Scattering System for ITER

Hatae, T.; Nakatsuka, Masahiro; Yoshida, Hidetsugu; Ebisawa, K.; Kusama, Y.; Sato, Kazuyoshi; Katsunuma, Atsushi; Kubomura, H.; Shinobu, K.

doi:10.13182/fst07-a1313

Cited by 16 publications

(4 citation statements)

References 12 publications

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“…This region is actually outside the specifications for the core system, but the proposed system actually has the best signal in this region, Therefore, what is the resolution required and can LIDAR-TS fill the gap of the 0.85 < r/a < 1? The specification of the Edge TS system is a resolution of 0.5 cm [8], the actual barrier region being several cm wide.…”

Section: Improved Edge Resolutionmentioning

confidence: 99%

LIDAR TS for ITER core plasma. Part III: calibration and higher edge resolution

Nielsen

Gowers

Salzmann³

2017

J. Inst.

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Calibration, after initial installation, of the proposed two wavelength LIDAR Thomson Scattering System requires no access to the front end and does not require a foreign gas fill for Raman scattering. As already described, the variation of solid angle of collection with scattering position is a simple geometrical variation over the unvignetted region. The additional loss over the vignetted region can easily be estimated and in the case of a small beam dump located between the Be tiles, it is within the specified accuracy of the density. The only additional calibration is the absolute spectral transmission of the front-end optics. Over time we expect the transmission of the two front-end mirrors to suffer a deterioration mainly due to depositions. The reduction in transmission is likely to be worse towards the blue end of the scattering spectrum. It is therefore necessary to have a method to monitor such changes and to determine its spectral variation. Standard methods use two lasers at different wavelength with a small time separation. Using the two-wavelength approach, a method has been developed to determine the relative spectral variation of the transmission loss, using simply the measured signals in plasmas with peak temperatures of 4–6 keV . Comparing the calculated line integral of the fitted density over the full chord to the corresponding interferometer data we also have an absolute calibration. At the outer plasma boundary, the standard resolution of the LIDAR Thomson Scattering System is not sufficient to determine the edge gradient in an H-mode plasma. However, because of the step like nature of the signal here, it is possible to carry out a deconvolution of the scattered signals, thereby achieving an effective resolution of ∼ 1–2 cm in the outer 10–20 cm.

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Section: Improved Edge Resolutionmentioning

confidence: 99%

LIDAR TS for ITER core plasma. Part III: calibration and higher edge resolution

Nielsen

Gowers

Salzmann³

2017

J. Inst.

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“…We have developed a double-line YAG laser system using heavy fluorocarbons SBS-PCM for Thomson scattering plasma diagnostics (Hatae et al, 2004(Hatae et al, , 2006a(Hatae et al, , 2006b. Figure 61 shows the optical layout of YAG laser system.…”

Section: Laser Applications Of Liquid Sbs-pcmmentioning

confidence: 99%

Trends in stimulated Brillouin scattering and optical phase conjugation

et al. 2008

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An overview on current trends in stimulated Brillouin scattering and optical phase conjugation is given. This report is based on the results of the "Second International Workshop on stimulated Brillouin scattering and phase conjugation" held in Potsdam/Germany in September 2007. The properties of stimulated Brillouin scattering are presented for the compensation of phase distortions in combination with novel laser technology like ceramics materials but also for e.g., phase stabilization, beam combination, and slow light. Photorefractive nonlinear mirrors and resonant refractive index gratings are addressed as phase conjugating mirrors in addition.

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“…Optical components such as mirrors and lenses for the Thomson scattering system were arranged based on the optical design [6]. The structure and the position of the BSM supports, on which the EM force on the BSM is induced mainly, have been considered to avoid the optical path through the BSM.…”

Section: Integration Of Diagnostics Into Upper Port Plugmentioning

confidence: 99%

Development of ITER Diagnostic Upper Port Plug

Sato

Ohmori

Ebisawa³

et al. 2007

Plasma and Fusion Research

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The designs and analyses of the diagnostic port plug for installing diagnostics have been carried out from various aspects in order to advance the port plug concept to the realistic design. Manufacturing processes have been studied for the alternative structure using the rolling plates and ribs, in addition to the reference structure using forging material. Electromagnetic loads onto the upper port plug during a vertical displacement event have been evaluated. It has been shown that maximum moments are about half of the reference ones. The design integration of three diagnostics into one of the upper port plugs has been performed by considering required aspects such as diagnostic functions, neutron shielding, maintenance of diagnostic components and cooling channels.

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Progress in Development of Edge Thomson Scattering System for ITER

Cited by 16 publications

References 12 publications

LIDAR TS for ITER core plasma. Part III: calibration and higher edge resolution

LIDAR TS for ITER core plasma. Part III: calibration and higher edge resolution

Trends in stimulated Brillouin scattering and optical phase conjugation

Development of ITER Diagnostic Upper Port Plug

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