Latest RGO Data for the EEV 42-80 CCD.

Spectral Response Data for Devices-
(42-10)5243/37/5, (42-80)5244/37/8 CCD.

EEV have produced a third 42-10, 512x2k device and the first working 42-80, (4kx2k) thinned 13.5um pixel device. This has been a significant move forward in our contract and the data here relates to the Spectral Response performance of both the interim package (42-10) device and the final packaged 42-80. The 42-80 has a similar Anti-Reflection coating to that of the smaller device... We are currently discussing with EEV the slight difference in response at the short-wavelength end of the spectrum. Their measurements are in reasonable agreement with our own data.

Current Noise Performance for the 42-80

This  data represents the noise performance obtained from
the 42-80 enginerring (yes engineering!) device we are currently operating. 


5244/37/8, 42-80
------------------------------------------------------------------------------
Gain (e/adu)        0.68         0.62         0.63       0.77       1.05     
Noise(rms e)        4.02         3.2          3.2        4.1        4.2  
Bias (adu)          12566        12633        12608      12436      12064         
CDS(Ref+Sig us)     20+20        10+10        5+5        2+2        1+1

NOTE:: System noise HAS been subtracted for these  measurements

The FET Gain for this device has come out at 2.7uV/e and is 
consistent with the measurements made at EEV for similar devices. 
NOTE: this is about a factor of 2 lower than expected (6uV/e has 
been quoted in the spec. for this chip)

Spot/Uniformity Measurements at Various Wavelengths

As promised last week I have now obtained data of filtered spots of light, imaged onto our EEV 4k CCD; the images here show the result. Unfortunately we have not yet manufactured the hardware to get the chip in the proper place in the cryostat. The chip package being rather deep (2cms) has resulted in us having to modify the supporting mechanical parts at the front of the cryostat to fit the chip centrally on the optical axis; this work is now in hand. So currently there is some vignetting of the chip due to the window and radiation shield. In addition our spot is only about 30mm in diameter at the CCD so it does not illuminate the whole chip. However, I managed to get the bottom half exposed at 350, 400, 600, 800 and 900 nm.

These are 4x4 binned frames, the only way to get the whole image onto the display in one go. Anyone know of any 4kx2k or even 2kx2k image displays!!

The spots all look pretty flat.. The black column at the top right is an artifact of XIMTOOL and nothing to do with the chip. The slight vignetting due to the radiation shield can be seen on the lower right of the spot as a slanting line, inclined inwards to the bottom. The horizontal under and overscans can also be clearly seen.

I plan to measure the flatness profile today, in preparation for a progress meeting at EEV tomorrow, across the 2k direction. I will put this data up on the Web Page early next week.

As usual the following images all have their associated full size counterparts...

Enjoy....

200 sec exposure at 350nm