Canis Major: ESO Test report

EEV 44-82 -1-A57
CCD name : Canis Major
Serial number : 9331-05-01
Type : Backside, Single layer AR Pixel size 15x15 µm
Number of photosensitive pixels 2048 x 4102 [HxV]
Number of outputs : 2
Overall rating :

Test date : February 27th 2001

 

Quantum Efficiency, PRNU

Clock mode: EEV 1p/225k/HG 512
Conversion Factor=   1.085e-/ADU  ±0.004     for 23870.2ADU
RMS noise        =   5.05e-      ±0.05

CCD temperature : -120Cº


Window area is : X1= 92 X2= 2042 Y1= 9 Y2= 501
Bandwidth 5nm

Wav.       QE%                   PRNU rms%       Phase =.                                                                                                    
320        46.3     ±1.3         4.33            7.491919                                                                                                  
330        52       ±1.5         4.1             7.427392                                                                                                  
340        54.7     ±1.1         3.99            7.394289                                                                                                  
350        55.5     ±0.54        4               7.394152                                                                                                  
360        57.1     ±0.56        3.99            7.398605                                                                                                  
370        60.8     ±0.6         3.56            7.287704                                                                                                  
380        68.4     ±0.68        2.55            6.953967                                                                                                  
390        75.3     ±0.77        1.88            6.643621                                                                                                  
400        78.8     ±0.8         1.51            6.414519                                                                                                  
420        81.9     ±0.83        1.19            6.156016                                                                                                  
440        83.1     ±0.83        1.08            6.044511                                                                                                  
460        82.3     ±0.62        1.03            5.985608                                                                                                  
480        81.6     ±0.82        0.957           5.901837                                                                                                  
500        81.4     ±0.82        0.944           5.894609                                                                                                  
520        81       ±0.81        0.913           5.863371                                                                                                  
540        79.8     ±0.8         0.898           5.855030                                                                                                              
560        78.4     ±0.78        0.898           5.866243                                                                                                  
580        78.1     ±0.78        0.898           5.875317                                                                                                  
600        76.8     ±0.76        0.913           5.903675                                                                                                  
620        75.9     ±0.75        0.959           5.966185                                                                                                  
640        74.6     ±0.73        1.05            6.067703                                                                                                  
660        72.4     ±0.7         1.13            6.156096                                                                                                  
680        70.4     ±0.67        1.24            6.246556                                                                                                  
700        67.4     ±0.63        1.34            6.318153                                                                                                  
720        64.8     ±0.6         1.64            6.509082                                                                                                  
740        61.7     ±0.56        2               6.675812                                                                                                  
760        57.9     ±0.52        2.11            6.749301                                                                                                  
780        54.1     ±0.47        2.47            6.851029                                                                                                  
800        48.9     ±0.42        2.33            6.842320                                                                                                   
840        39.7     ±0.33        2.45            6.886485                                                                                                  
900        25.8     ±0.21        3.09            7.141034                                                                                                  
940        15.9     ±0.2         4.98            7.612813                                                                                                  
1000       4.46     ±0.04        9.19            8.201900                                                                                                    
1040       0.709    ±0.006       9.61            8.284498                                                                                                  
1100       0.0799   ±0.0006      11.2            8.484301

Table 1: Measurement of the Quantum Efficiency

Figure 1: Graphic representation of the QE.
Figure 2: Graphic representation of the PRNU.

Quantum efficiency, comparison

In this section you can compare the QE we measured with the testbench and
Figure 3: Comparison between the QE measured by ESO, the QE measured by Marconi,
ESO specification and minimum specification.

Difference between QE measurements made by ESO and Marconi.

Comparison QE ESO / QE Marconi

Wavelength (nm)

QE ESO (%)

QE Marconi (%)

Difference (Eso - Marc. %)

Relative difference (Marconi as reference %)

350

65.5

57

8.5

14.9

400

80.8

79

1.8

2.3

500

80.1

81

-0.9

-1.1

650

72.55

73.6

-1.05

-1.4

900

26.6

28

-1.4

-5.0

Table 2: Difference and relative difference between ESO measurement and Marconi.
Figure 4: Graphic representation of the difference and the relative difference.

Cosmetic defects

Flat field

For the flat field we use three wavelengths, 350nm, 600nm and 900nm. For each wavelength we make two images, high level (45000 ADU) and low level (1000 ADU).

350nm (UV), bandwidth 5nm

600nm, bandwidth 5nm

900nm, bandwidth 5nm

High level
Low level
High level
Low level
High level
Low level

Table 3: Flat field for three wavelengths.

Bias and dark

The time exposure, for the long dark exposure, is 3600 seconds.

Bias

Long exposure dark image

Table 4: Bias and dark.

Readout noise/Conversion factor

Clock mode: EEV 1p/225k/HG 512
Conversion Factor=   0.54124e-/ADU ±0.001338     for 20413ADU                                                                    
RMS noise        =   4.9916e-      ±0.2453

Clock mode: EEV 1p/50k/HG 512
Conversion Factor=   0.59002e-/ADU ±0.001296     for 19716.7ADU                                                                  
RMS noise        =   2.6797e-      ±0.2151
Clock mode: 50kpx

Left readout port
Conversion Factor=   0.59076e-/ADU ±0.004003     for 20497.4ADU                                                                  
RMS noise        =   2.6505e-      ±0.1957

Linearity (TDI method)

RMS non linearity (%)         =    0.184268                                                                                      
Peak to peak non linearity (%)=    0.559288

Figure 5: Error of linearity

Figure 6: Residual non linearity.

Dark current

Exposure time (s) = 3600
Dark current : 0.30 ± 0.01 e-/hour/pixel

Charge Transfer Efficiency (CTE)

High level
Horizontal CTE = 0.999994
Vertical CTE = 0.9999995

Low level
Horizontal CTE = 0.999968
Vertical CTE = 0.999998

Cosmetic defects

In this section we expose the hot pixel, the dark pixel, the trap and the very large trap we found and how.

Hot pixel

A hot pixel provides a signal of > 60 e- / pixel / hour. To have these point we use a median dark image.


Result: Two hot pixels.


On our images this point is to the coordinates:


Position

Image

Histogram around the hot pixel

X= 0624; Y= 3774

X= 0189; Y= 2843

Table 5: Position and images of the hot pixels. The values in the table are in ADU. Conversion factor: 1.1 e-/ADU.

Dark pixel

A dark pixel is one with 50% or less than the average output for uniform intensity light level, measured with a flat field level around 500 photo-electrons.


Result: No dark pixel detected.

Trap

A trap is defined as a pixel that captures more than 10 electrons, measured with a flat field level around 500 photo-electrons.


Result: No trap detected.

Very large trap

A very large trap is defined as a pixel that captures more than 10 000 electrons, measured with a flat field level around 90% of full well capability.


Result: One very large trap.


On our images this point is to the coordinates:


Position

Image

Histogram around the very large trap

X= 1929; Y= 0141

Table6: Position and images of the very large trap.

Bad column

A bad column is 10 or more contiguous hot or dark pixels in a single column or a very bright pixel or a very large trap.


Conclusion

Here is a summary of cosmetic defects:


Hot pixel

Dark pixel

A very bright pixel (a)

Trap

Very large trap (b)

Bad column (c)

Total bad column (a+b+c)

ESO

2

0

/

0

1

0

1

Marconi

39

4

1

1

0

5

Table 7: Summary of cosmetic defects.


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