TJ-II:Fast camera: Difference between revisions
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Here are some examples of movies recorded with the fast camera system of TJ-II. | Here are some examples of movies recorded with the fast camera system of TJ-II. | ||
=== Dust === | |||
[[File:polvo1b.gif]] | [[File:polvo1b.gif|frame]] | ||
First insertion of the poloidal limiter after a lithiation of the vacuum vessel. The ejection of lithium flakes from the carbon surface can be seen clearly at the beggining 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 post-discharge plasmoid. | First insertion of the poloidal limiter after a lithiation of the vacuum vessel. The ejection of lithium flakes from the carbon surface can be seen clearly at the beggining 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 post-discharge plasmoid. | ||
Revision as of 15:19, 8 March 2011
TJ-II disposes of different fast camera systems for plasma imaging [1] [2] [3]. The main system is located in sector B8, port B8TANG, viewing tangentially the poloidal limiter in sector C3.
Cameras
The newest fast camera employed at TJ-II is a Photron SA1 camera. Sampling speed (measured in frames per second, fps) and image size can be selected, but there is a trade-off:
- 5000 fps with 1024 x 1024 pixels(full frame)
- 10000 fps with 512 x 512 pixels
- 200000 fps (maximum ever employed so far) with 182x80 pixels
The dynamic range of the sensor is 8 bits, and the memory size is 8 GB.
Image Intensifier for Fast Camera
A Hamamatsu C9548-03BL series image intensifier is used. This is a two stage intensifier, including a first GEN II stage with a fast phosphor (P-46) and gain adjustable via the voltage at the MCP, and a second GEN I one (booster) with a fixed gain of 50 and somewhat slower phosphor screen (P-24). Both stages are optically coupled by a Fiber Optic Plate (FOP) which transfers the output signal from the first to the second.
Videos
Here are some examples of movies recorded with the fast camera system of TJ-II.
Dust
First insertion of the poloidal limiter after a lithiation of the vacuum vessel. The ejection of lithium flakes from the carbon surface can be seen clearly at the beggining 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 post-discharge plasmoid.
References
- ↑ J.A. Alonso et al, Impact of different confinement regimes on the two-dimensional structure of edge turbulence, Plasma Phys. Control. Fusion 48 (2006) B465-B473
- ↑ D. Carralero et al, Turbulence studies by fast camera imaging experiments in the TJII stellarator, Journal of Nuclear Materials 390-391 (2009) 457-460
- ↑ E. de la Cal et al, The visible intensified cameras for plasma imaging in the TJ-II stellarator, Contrib. Plasma Phys. (2010)