Chip name                                      EEV10a

Year of manufacture                   1997

Serial number                              7043-16-4

First light on La Palma                March 1998

Description                                  EEV42 thinned.

Modifications to EEV10a by SMT 27th May 1999

There were a number of problems with the original EEV10a related to poor noise performance and poor matching of the signal processor gain to the dynamic range of the CCD. The following hardware modifications were made.
1.    The outer sheath of the short grey cable connecting cryostat to pre-amp was grounded to pre-amp chassis.
2.    R31,32,33,34 in the pre-amp all has 4K7 resistors soldered in parallel.
3.    R5 on the CDS was replaced with 50K.
4.    R12 & R13 on the CDS were replaced with 3K9
5.    C7,C8 on CDS card were replaced with 1000pF

The standard, Quick and Turbo pixel routines ( pages 9,10 & 11 of ram-disk ) were replaced with those used on EEV12. The RD voltage was increased to 4.5V and OD reduced to 16V. THe rest of the RAM-DISK was unchanged.

The effect of the changes was to reduce the read noise, remove pattern noise, decrease the readout time and increase the dynamic range.
 
 

 
 

	Noise (e)	Gain (e/ADU)	Bias (ADU)	Linearity (1%)	Readout time (s)
Standard	4.2	1.17	794	65000	225
Quick	4.7	1.56	734	65000	180
Turbo	5.7	2.48	675	44000	165

Vertical CTE                                              >0.999999

Horizontal CTE                                          >0.999999

Pixel Scale (isis blue)                                   0.19 arcsecs/pixel

X Pixel size                                                    13.5 microns

Y Pixel size                                                    13.5 microns

X size in pixels of digitised area                2148

Y size in pixels of digitised area                4148

X size of useful imaging area                    2048

Y size of useful imaging area                       4100

X start of useful imaging area                   50

Y start of useful imaging area                   0

LN2 capacity of cryostat                           2.5 litres

Cryostat window thickness                        4 mm

Distance from window to CCD                   10 mm

Cryostat window size                                 36 x 66 mm

Operating temperature                             153K

Preferred amplifier                                    L( R provides the same performance )

Network name                                            CCD1

Anti-blooming available                                    no

Quantum Efficiency

Full QE curve for EEV4280 in tabulated form, measured at ATC March 99

Dark current                          4 e/hour @ -120 degrees C

Full well bloom limit           ~150000 electrons

Chip flatness                           Profile scan shows centre section to be flat to < 1 micron

Cosmetics                               There are about 2ish pixel/column defects plus a cluster of single pixel  defects.

Cosmic Ray count                 1.6 events/cm²/min.