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TJ-II:Fast camera: Difference between revisions
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In the framework of EUROFUSION program, the group has leaded the installation and operation of the KL8 Wide Angle Visible Fast Camera in '''JET Tokamak''' (UK). | In the framework of EUROFUSION program, the group has leaded the installation and operation of the KL8 Wide Angle Visible Fast Camera in '''JET Tokamak''' (UK). | ||
The latest upgrade and experiments with the ITER like Wall (ILW) are described elsewhere <ref name=" | The latest upgrade and experiments with the ITER like Wall (ILW) are described elsewhere <ref name="delaCal5">[http://ocs.ciemat.es/epsicpp2012pap/pdf/P5.041.pdf E. de la Cal et al et al, ''The Visible Intensified Fast Camera with Wide-angle view of JET ILW experiment'', 39th EPS Conference & 16th Int. Congress on Plasma Physics P5.041]</ref>. | ||
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=== Two-dimensional imaging of n<sub>e</sub> and T<sub>e</sub> showing ELM-like Edge Bursts<ref name="delaCal4"> </ref>=== | === Two-dimensional imaging of n<sub>e</sub> and T<sub>e</sub> showing ELM-like Edge Bursts<ref name="delaCal4"> </ref>=== | ||
[[File:25623wComm_Photo000001.jpg|700px|link=http://www-fusion.ciemat.es/fileshare/doc_exchange/camaras/HeliumRatio_ELMs.m4v | [[File:25623wComm_Photo000001.jpg|700px|link=http://www-fusion.ciemat.es/fileshare/doc_exchange/camaras/HeliumRatio_ELMs.m4v]] | ||
An intensified visible camera looks tangentially at a poloidal limiter where helium recycles, acting as a wide neutral source, and the atomic line emission due to plasma excitation becomes strongly localized there. It includes a bifurcated coherent bundle, each end with a different interference filter to select helium atomic lines, so that two simultaneous filtered images are captured in one single frame. The object of the proposed technique is to apply the well-known helium-beam line-ratio technique to obtain from selected filtered images the two-dimensional (2D) edge plasma n<sub>e</sub> and T<sub>e</sub>. | An intensified visible camera looks tangentially at a poloidal limiter where helium recycles, acting as a wide neutral source, and the atomic line emission due to plasma excitation becomes strongly localized there. It includes a bifurcated coherent bundle, each end with a different interference filter to select helium atomic lines, so that two simultaneous filtered images are captured in one single frame. The object of the proposed technique is to apply the well-known helium-beam line-ratio technique to obtain from selected filtered images the two-dimensional (2D) edge plasma n<sub>e</sub> and T<sub>e</sub>. | ||
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=== Dust Visualisation <ref name="delaCal3"> </ref>=== | === Dust Visualisation <ref name="delaCal3"> </ref>=== | ||
[[File:Dust.png|700px|link=http://www-fusion.ciemat.es/fileshare/doc_exchange/camaras/delaCal_dust.mp4]] | |||
Dust is observed in the TJ-II stellarator with a fast camera equipped with a bifurcated coherent fibre-bundle system that allows different set-ups such as dual filtering of atomic lines or a stereoscopic view to obtain tangential and perpendicular (to the magnetic field) observations simultaneously. The camera looks to a poloidal limiter that can be biased and it is observed that when a negative voltage is applied, dust from the limiter is ejected intensely once a certain threshold voltage is exceeded. | Dust is observed in the TJ-II stellarator with a fast camera equipped with a bifurcated coherent fibre-bundle system that allows different set-ups such as dual filtering of atomic lines or a stereoscopic view to obtain tangential and perpendicular (to the magnetic field) observations simultaneously. The camera looks to a poloidal limiter that can be biased and it is observed that when a negative voltage is applied, dust from the limiter is ejected intensely once a certain threshold voltage is exceeded. | ||
[[File: | [[File:Polvo1b.jpg|300px|link=media:Polvo1b.gif|Dust movie]] | ||
First insertion of the poloidal limiter after a lithiation of the vacuum vessel. Tangential observation, 15 kHz sampling rate. The ejection of lithium flakes from the carbon surface can be seen clearly at the beginning of the discharge. At the end of the video, as the plasma becomes colder, the flakes penetrate deeper into it until they float freely in the collapsing discharge. | First insertion of the poloidal limiter after a lithiation of the vacuum vessel. Tangential observation, 15 kHz sampling rate. The ejection of lithium flakes from the carbon surface can be seen clearly at the beginning of the discharge. At the end of the video, as the plasma becomes colder, the flakes penetrate deeper into it until they float freely in the collapsing discharge. | ||