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INT Wide Field Camera with UltraDAS + SDSU Gen.2


NB these figures refer to INTWFC when it was used with a Gen. 2 controller. Converted to Gen. 3 on the 1st. March 2007

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
Autoguider CCD details
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

Only one readout speed at present. Readout time 37s + processing 11s + writing to disk 8s = total 56s

CCD
Noise(e)

Noise(ADU)
Gain(e/ADU)
Bias
1
5.9

2.1
2.8
1527
2
6.9

2.3
3.0
1590
3
8.5

3.4
2.5
1623
4
6.4

2.2
2.9
1644

Linearity Data (Courtesy Mike Irwin)

Shutter please note the shutter timing becomes unreliable below 2s.

Binning and windowing are not permitted with this camera.

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) 2154
Y size of digitised area in pixels (each ccd) 4200
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 ) 54
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

Preferred 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)

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 in tabulated 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 

The graph below shows dark current remnance after the camera was flooded through a V filter for 60 seconds using the dome lights. NB dark current remnance from inadvertant exposure to dome lights is likely to be a major source of dark current for at least 5 hours.


 

Cryostat Pressure

The graph below shows the INTWFC cryostat pressure over a 2 month period after pumping.


 

Fringing. 5% in 'I' , 20% in 'Z'

Full Well Bloom Limit  200000e

Cosmic Ray Count ~2000 counts/hour/chip at sea-level

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)

Pretty Pictures

M101
M13
M8
M81

M42 Courtesy of Nik Syzmanek.
 


See "Another view of M33" by Romano Corradi.


NGC3242 by Romano Corradi.



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Last modified: 07 February 2014
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