VIMOS Scientific CCD System

CCD Test Report "SHERYL"

CCD Specification

CCD alias name :	SHERYL
Type :	EEV 44-82, backside illuminated, single layer AR coated
Number of photosensitive pixels :	[H] 2048, [V] 4102
Number of outputs :	2
Pixel size :	15 x 15 microns
Overall rating :	Science

Readout Noise and Conversion Factor

	Readout Speed ( kps )	Readout Noise ( e^- rms )	Conversion factor ( e^- / ADU )
Port A ( left bottom )	357	5.13 ± 0.02	1.90 ± 0.06
Port B ( right bottom )	357	5.22 ± 0.02	1.82 ± 0.06

Quantum Efficiency

Wavelength [nm]	PRNU	QE [%]
320	2.2	40
340	2.0	46
360	2.0	51
380	1.3	68
400	0.9	81
450	0.7	91
500	0.6	92
550	0.6	88
600	0.6	88

Wavelength [nm]	PRNU	QE [%]
650	0.6	85
700	0.6	77
750	0.6	69
800	0.6	58
850	0.6	44
900	0.7	28
950	1.7	15
1000	4.6	5
1100	6.3	0.1

Cosmetic Defects

Low Level Flat Field Mean number of electrons per pixel » 4.000
Type of Defect :	Location (x,y) :	Number of pixels affected :
Trap	1407,2716	1.380

Bias Image 0 sec. dark exposure, 1.372 pixels above 5 s
Type of Defect :	Location (x,y) :	Number of pixels affected :
Hot column	1588,2428	1.668

Long Exposure Dark Images 5 exposures of 3.600 sec. each, 183 pixels above 5 s
Type of Defect :	Location (x,y) :	Number of pixels affected :
Hot pixels cluster	1588,2427	50
Hot pixels column	747,2236	40

Notes :

Electroluminescence visible when using 26 V on OD on right amplifier, disappears with OD £ 25 V.

Q-tips cleaning trail visible (due to EEV).

Images

All images got the serial register at the bottom of the image. All are full frames images including 50 pixels of X-pre-/overscan and 100 pixels of Y-overscan.

All images are full frames (1 CCD pixel = 1 screen pixel) otherwise mentionned.

Bias frame

Dark frame (5 median stacked 1 hour exposure dark frames)

Cosmetics (Flat fields from the 60 cm diameter integrating sphere)

800 nm, 1 nm bandwidth

600 nm, 4 nm bandwidth

Linearity

	Speed ( kps )	Non-Linearity		Range ( ADU )	Saturation level ( e^- )
		Peak - Peak ( % )	Rms ( % )
Port A ( left bottom )	357	+ 0.32 / - 0.40	0.2	0 - 55000	222 K
Port B ( right bottom )		+ 0.16 / - 0.30	0.11		217 K

Dark Current

Mean dark current 1.1 ± 0.1 e^-/pixel/hour @ - 120 °C.
Exposure time used in frames : 5 exposures of 3.600 sec. each.

Notes : Very clean dark frame.
No remanence visible after CCD exposed to room light and reading-out Bias after 2 minutes.

Cosmic Ray Hit Event

Cosmic hit event rate :

21 ± 0.4 events/min/CCD;
1.15 ± 0.02 events/min/cm².

Charge Transfer Efficiency

Vertical CTE to port A/B : 0.9999988 (almost six 9 s);
horizontal CTE to port A/B : 0.9999995 (six 9 s, 5).

Measurement Conditions

Prescan :

[H] 50, [V] 0

Overscan :

[H] 50, [V] 70

Temperature :

- 120 °C

Bias Voltages (V) :

	Port A (left bottom)	Port B (right bottom)
RD	13.0	13.0
OD	25.0	26.0
JD	25.0	26.0
IF	- 8 ® + 4	-

Gain (Port A, B) :

Stage 1 = 2.25,
Stage 2 = 5.0

General Comments :

No error bars available for QE measurements.
Glowing from amplifier may occur if OD > 25.

Report Date :

27/April/1999

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