FORS 2 - CCD System

Linearity

	Speed ( kps )	Non-Linearity Peak - Peak ( % )		Range ( ADU )	Saturation level ( e^- )
	Speed ( kps )	Peak - Peak ( % )	Rms ( % )	Range ( ADU )	Saturation level ( e^- )
Port A ( left bottom )	50 ( high gain )	+ 0.45 / - 0.48	0.23	220 - 65535	120 K
Port A ( left bottom )	50 ( low gain )	+ 0.40 / - 0.31	0.20	220 - 65535	171 K
Port B ( left bottom )	50 ( high gain )	+ 0.72 / - 0.62	0.36	220 - 65535	130 K
Port B ( left bottom )	50 ( low gain )	+ 0.65 / - 0.38	0.30	220 - 65535	183 K
Port C ( left bottom )	50 ( high gain )	+ 0.46 / - 0.57	0.29	220 - 65535	119 K
Port C ( left bottom )	50 ( low gain )	+ 0.24 / - 0.27	0.15	220 - 65535	174 K
Port D ( left bottom )	50 ( high gain )	+ 0.68 / - 0.73	0.42	220 - 65535	119 K
Port D ( left bottom )	50 ( low gain )	+ 0.68 / - 0.73	0.21	220 - 65535	170 K

Linearity Error

The graph shows the linearity error (%) according to illumination level in ADUs (port C, low gain, residual errors).

Dark Current

Mean dark current 4.2 ± 0.4 e^-/pixel/hour @ - 120 °C.

Cosmic Ray Hit Event

Cosmic hit event rate :

61 ± 8 events/min/CCD;
2.4 ± 0.3 events/min/cm².

Exposure time used in frames : 9 exposures of 3.600 sec. each.
Remanance is visible after room light exposition, it requires 15 min. to recover.

Note : Very clean darks.

Charge Transfer Efficiency

Vertical CTE to port A/B : 0.999999995 ( almost nine 9s ) ;
horizontal CTE to port A : 0.99999981 ( almost seven 9s ).

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Last update: Mar 16, 2004
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