Design of a Gas-Puff Imaging Diagnostic for W7-X
| Autor: | Terry J., Baek S.G., Ballinger S.B., von Stechow A., Grulke O., Scarin P., the W7-X-team |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
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| Zdroj: | 60th Annual Meeting of the APS Division of Plasma Physics, Portland, Oregon, November 5-9, 2018 info:cnr-pdr/source/autori:Terry J.; Baek S.G.; Ballinger S.B.; von Stechow A.; Grulke O.; Scarin P.; the W7-X-team/congresso_nome:60th Annual Meeting of the APS Division of Plasma Physics/congresso_luogo:Portland, Oregon/congresso_data:November 5-9, 2018/anno:2018/pagina_da:/pagina_a:/intervallo_pagine |
| Popis: | A Gas-Puff-Imaging (GPI) diagnostic is being designed for use on the W7-X Stellarator. It will allow for detailed study of boundary and scrape-off-layer physics during the long-pulse W7-X operation period OP 2. GPI requires an in-vessel nozzle close to the plasma, through which non-perturbing amounts of H2 or He gas are puffed; a re-entrant view of the puff, ideally along local field lines; and an optical system that relays the imaged emission to a fast 2D detector. This must be done in the harsh long-pulse environment, where re-entrant hardware must be actively cooled and collecting optics shuttered. We have prepared a design for viewing a roughly 50 x 70 mm region at the plasma boundary with spatial resolution of ~5 mm and time resolution of ~1 ?sec. We propose to puff the gas through 4 converging-diverging nozzle apertures in order to collimate the gas cloud. We have performed finite-element analysis of fluid flow down the feed tube and through the nozzles. We have modeled the puff emission using DEGAS 2. We have designed a water-cooled re-entrant tube to hold the light collection optics and modeled the optics to attain sufficient resolution and light throughput. The details of the design and modeling will be shown. |
| Databáze: | OpenAIRE |
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