Anti Blooming

[Simon Tulloch]

Dear Roger

Thankyou for your response to my queries concerning anti-blooming clocks with 
TEK 1024 CCDs. The bright spots do not flat field out well due to their shot noise 
contribution, although their heights and positions are fairly repeatable.

 I agree that smoothing of the clock edges by the distributed RC properties of the 
parallel clock electrodes must be responsible for the enhanced dark current only 
appearing close to the bond pads (i.e. in regions close to row 512). The clock edges 
can be adjusted over the range 500ns to 30us with our controller. Within this range 
the enhanced dark current does not change. This suggests to me that the 'on-chip' 
smoothing of the clock waveforms must increase  the clock edges to beyond 30us.


Regards

Simon Tulloch

Royal Greenwich Observatory
Madingley Road
Cambridge
CB3 OEZ
UK