INT WFC

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. Converted to SDSU Generation 3 1/4/07.

Operational Characteristics

FAST readout 29 seconds
CCD	Noise (e)	Noise (ADU)	Gain (e/ADU)	Bias
1	9	3.6	2.5	1830
2	9.5	2.8	3.4	1810
3	7.7	3.2	2.4	1835
4	9.1	2.8	3.25	1810

SLOW readout 48 seconds
CCD	Noise (e)	Noise (ADU)	Gain (e/ADU)	Bias
1	4.6	3.7	1.26	2030
2	4.8	2.8	1.7	2080
3	4.3	3.6	1.2	2070
4	4.3	2.6	1.67	2060

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

Binning and windowing are 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 :

CCD2 : column = 2000, row = 100

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