An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 2 Search : dark current
dark current
  جریان ِ تاریکی   
jarayân-e târiki

Fr.: courant d'obscurité   

Current generated in an electronic detector by thermal effects, even in the absence of input signal. In a → CCD detector, the current rises from thermal energy within the silicon lattice comprising the CCD. These electrons are captured by the CCD's potential wells and counted as signal. → dark current noise.

dark; → current.

dark current noise
  نوفه‌ی ِ جریان ِ تاریکی   
nufe-ye jarayân-e târiki

Fr.: bruit du courant d'obscurité   

In a → CCD detector, statistical fluctuation of the → dark current, equal to the square root of the dark current. CCDs can be cooled either with thermoelectric coolers or liquid nitrogen to reduce this effect. Ideally, the dark current noise should be reduced to a point where its contribution is negligible over a typical exposure time.

dark; → current; → noise.