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Warning : these figures refer to WFC when it was used with a Dutch controller and are for reference only.

WFC Parameters



Device Identification

Mosaic name                              INT WFC

Year of manufacture                  1998

Serial numbers                           CCD1  A5506-4,   CCD2  A5383-17-7,   CCD3  A5530-3,   CCD4  A5382-1-7

First Light on La Palma           April 1998

Description                                 The INT Wide Field camera is a 4 Chip Mosaic of thinned AR coated EEV 4K x 2K devices.

Operational Characteristics

SLOW READOUT SPEED (168 seconds) writes turbo in header
 
CCD
Noise(e)
Gain(e/ADU)
Linearity(max ADU +/-2%)
Bias
1
7.4
3.2
55k
1601 
2
6.4
3.2
57k
1682 
3
7.7
2.9
57k
1296 
4
8.3
3.3
56k
1226 
STANDARD READOUT SPEED (155 seconds) writes non-astro in header.


CCD
Noise(e)
Gain(e/ADU)
Linearity(max ADU +/-2%)
Bias
1
6.0
3.4
54k
1114
2
7.4
3.4
51k
1454
3
7.0
3
56k
1544
4
9.0
3.5
50k
1159

BINNED 2x2 (65 seconds)


CCD
Noise(e)
Gain(e/ADU)
Linearity(max ADU +/-2%)
Bias
1
7.7
3.0
60k
2
6.6
2.9
58k
3
8.9
2.8
(possibly non-linear)
4
8.9
2.86
57k

Physical Characteristics

Pixel Scale                                                            0.333 arcsec/pixel

Field of view                                                         34 x 34 arcmin

Pixel Size                                                              13.5 microns x 13.5 microns

X size of digitised area in pixels (each ccd)          2148

Y size of digitised area in pixels (each ccd)          4128

X size of useful imaging area ( each ccd )             2048

Y size of useful imaging area ( each ccd )             4100

X start of useful imaging area ( each ccd )            50

Y start of useful imaging area ( each ccd )            0

LN2 capacity of cryostat                                                6 litres

Cryostat window thickness and distance of chips from window.

Details of gaps between image areas of mosaic elements.

Operational Parameters

Operating temperature                                                 -153K

Prefered amplifier - all CCDs have 2 working amplifiers, however, CCD1 shows very poor HCTE when using right hand amp. so all 4 EEVs are read out using the left hand amp. (28/4/98)

Anti-blooming - this is available and removes or reduces the effects of saturated stars blooming up and down a column, it can only be en/disabled by the duty engineer. ( block 18 of ram-disk )

Measured Characteristics

Quantum Efficiency ( @-120C )
 
 

Wavelength
380nm
400nm
650nm
950nm
CCD1
67
80
75
13
CCD2
72
87
79
15
CCD3
62
80
80
14
CCD4
61
78
86
16

Full QE curve for EEV4280 measured at ATC March 99 
 

Dark Current

Measured in electrons per pixel per hour
 
 

CCD1 
CCD2 
CCD3 
CCD4 
-110 Centigrade 
3.8 
3.3 
2.9 
2 
-120 Centigrade 
0.5 
0.7 
0.3 
0.5 
Fringing                                      5% in 'I' , 20% in 'Z'

Full Well Bloom Limit                  200000e

Chip flatness and Co-planarity

Individual EEV CCDs have a convex bow of between 6 and 10 microns. The mosaic co-planarity is within +/-20um. It is recommended that when focusing the camera, stellar images should be optimally focused at the three points :

        CCD1 : column = 1400,  row = 500

        CCD2 : column = 2000,  row = 100

        CCD3 : column = 1500,  row = 370       (co-ordinates assume use of left hand amplifiers)
         

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Last modified: 21 November 2010