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TJ-II:Fast camera: Difference between revisions
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[[File:camaras1.png]] | [[File:camaras1.png]] | ||
[[File:camaras2.png| | [[File:camaras2.png|500px|]] | ||
== Image Intensifier for Fast Camera== | == Image Intensifier for Fast Camera== | ||
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Below are some examples of movies recorded with the fast camera system of TJ-II. Click on the images to see the corresponding movie. | Below are some examples of movies recorded with the fast camera system of TJ-II. Click on the images to see the corresponding movie. | ||
=== Double imaging to visualize the fine structure of Blobs<ref name="delaCal2"></ref>=== | === Double imaging to visualize the fine structure of Blobs<ref name="delaCal2"> </ref>=== | ||
[[File:Double_Imaging.jpg|700px|link=http://www-fusion.ciemat.es/fileshare/doc_exchange/camaras/video_DOUBLE_IMAGING.mp4]] | [[File:Double_Imaging.jpg|700px|link=http://www-fusion.ciemat.es/fileshare/doc_exchange/camaras/video_DOUBLE_IMAGING.mp4]] | ||
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To distinguish real physical signal from noise we get two simultaneous images with the same view and compare them. We call this Double Imaging technique and it allowed us to validate the detected blob shape to scales down to a few millimetres, limited by our optical resolution. | To distinguish real physical signal from noise we get two simultaneous images with the same view and compare them. We call this Double Imaging technique and it allowed us to validate the detected blob shape to scales down to a few millimetres, limited by our optical resolution. | ||
=== Two-dimensional imaging of n<sub>e</sub> and T<sub>e</sub><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/camaras/25623wComm.avi|Limiter recycling movie]] | [[File:25623wComm_Photo000001.jpg|700px|link=http://www-fusion.ciemat.es/camaras/25623wComm.avi|Limiter recycling movie]] | ||
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TJ-II plasma observed from a tangential port at 17.5 kHz sampling rate, with a lithium filter and image intensifier. In the field of view, the two most prominent areas of plasma-wall interaction can be seen: the poloidal limiter (lower) and the hardcore (helical limiter). As the plasma transits form ECH to NBI plasmas, the interaction level diminishes and becomes predominantly centered in the limiter. <ref name="Carralero"></ref> From the lithium emission fluctuations information on the electron density fluctuations can be gained. <ref name="delaCal"></ref> | TJ-II plasma observed from a tangential port at 17.5 kHz sampling rate, with a lithium filter and image intensifier. In the field of view, the two most prominent areas of plasma-wall interaction can be seen: the poloidal limiter (lower) and the hardcore (helical limiter). As the plasma transits form ECH to NBI plasmas, the interaction level diminishes and becomes predominantly centered in the limiter. <ref name="Carralero"></ref> From the lithium emission fluctuations information on the electron density fluctuations can be gained. <ref name="delaCal"></ref> | ||
=== Dust Visualisation <ref name="delaCal3"></ref>=== | === Dust Visualisation <ref name="delaCal3"> </ref>=== | ||
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. | ||
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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 | 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. | ||
[[File:Polvo1b.jpg|300px|link=media:Polvo1b.gif|Dust movie]] | [[File:Polvo1b.jpg|300px|link=media:Polvo1b.gif|Dust movie]] | ||