[ ESO ]

3.6 / EFOSC II / CCD Loral/Lesser #40

  
HOME INDEX SEARCH HELP NEWS

 
TYPE Loral/Lesser 
Thinned, AR coated,UV flooded, MPP
IMAGE SIZE [pixels] 2048 x 2048 (0 prescan pixels in horizontal direction) 
PIXEL SIZE [microns] 15 x 15
DARK CURRENT [e- / pixel / hr]  <1 at 140 K
FULL WELL CAPACITY [e- / pixel] 104k
CONTROLLER ESO FIERA
Mode normal [27 kpixel / sec] fast [60 kpixel / sec] very fast [97 kpixel / sec]
R.O.N. [e- rms] 7.5 8.5 13
CONVERSION FACTOR [e- / ADU] 1.3 1.4 1.4
Full Frame READOUT TIME [sec] 160 70.5 44


Quantum efficiency

 

Linearity

The CCD system (CCD + FIERA controller) shows a linearity better than ± 0.4 % over the full range of the 16 bit analog to digital converter (ADC). The system linearity has been explored in a range of 2000e up to 83000e.

The electronics have been tuned so that the ADC will saturate before non-linearity is reached.

(in electrons)
Normal
Fast
Very fast
CF
1.35
1.35
1.38
ADU RON
7.8
8.2
12.7

 

Charge Transfer Efficiency

Serial CTE = 0.999998 and Parallel CTE = 0.99998

Full Well Capacity

Amplifier 1:
Upper limit of linearity: 104 ke-/pixel
Saturation-value: 162 ke-/pixel
Amplifier 2:
Upper limit of linearity: 92 ke-/pixel
Saturation-value: 153 ke-/pixel
Cosmic Ray Event

The cosmic ray event rate is 1.9 [events / min / cm ²]

Remanence

Exposure Exposure Illumination CCD Remanence
Type Time in Satu- in
in [sec] [photons/pixel] ration [e-/pixel]
FF white 1(Dens=1) 75000 0.32 ---
DK 600 -- -- 1
FF white 1 664000 2.88 ---
DK 600 -- -- 9
DK 600 -- -- 3
DK 600 -- -- 2
FF white 10 6640000 28.8 ---
DK 600 -- -- 12
DK 600 -- -- 4
DK 600 -- -- 2
Table:   Remanence of the CCD at 158 K

The Remanence test was made after 10 hours in the dark and periodical wiping at at temperature of 158 K. After a high level flat field with white light which give over-saturation on the CCD, several ten minutes dark exposures have been taken. The mean level in the centre of these dark exposures was compared with the mean level of a ten minute dark before these saturations and the remanence in e-/px has been calculated The results can be seen in the table above

Uniformity

The homogeneity was measured using a standard method of sampling the whole sensitive area and using the RMS value of it. Values of deviations from homogeneity are given in the table below

Flat-field exposure
at wavelength in [nm]		 Maximal RMS Deviation
from mean value [%]
320 5.36
340 4.45
360 4.23
380 4.36
400 4.54
450 4.16
500 4.04
550 3.82
600 3.98
650 4.10
700 3.71
750 3.81
800 3.90
850 3.69
900 3.73
950 3.94
1000 4.13
1040 5.21
1080 5.32
1100 4.37
Table:Uniformity of the CCD

Amplifier 1

All measurements done with weak light images (300 e-/px)

No hot spots, cluster and columns noticed.

52 dark pixels, 295 dark cluster, 66 dark columns and 262 traps

Amplifier 2

All measurements done with weak light images (300 e-/px)

No hot spots, cluster and columns noticed.

37 dark pixels, 311 dark cluster, 65 dark columns and 307 traps


Weak Flat Field at 700 nm with Amplifier 2.

 

History

In August 1998 EFOSC 2 was upgraded to use a FIERA controller.

It was transferred to the 3.6m telescope in December 1997 and it is thus not available anymore at the 2.2 m telescope.

Date of last set of tests at the 2.2 m telescope: May 4, 1997
Date of delivery at the 2.2 m telescope: August 1996

 
Previous test: May 4, 1997
DARK CURRENT [e- / pixel / hr] 5.46 at 140 K
Mode slow [17 kpixel / sec] fast [38 kpixel / sec]
R.O.N. [e- rms] 6.3 7.8
CONVERSION FACTOR [e- / ADU] 1.6 1.3
Previous test: August 31, 1996
DARK CURRENT [e- / pixel / hr] 5.46 at 140 K
Mode slow [17 kpixel / sec] fast [38 kpixel / sec]
R.O.N. [e- rms] 6.21 7.8
CONVERSION FACTOR [e- / ADU] 1.6 1.34



Image Files
©   1999 by Cyril Cavadore

Send comments to   odt@eso.org
Last update: 2004/Mar/24

 [ESO Web Policy Documents] [ESO] [Index] [Search] [Help] [News]