Marks on Loral CCD

[Michael P. Lesser]

Hi Paddy,

The scratches are artifacts of the oxidation process and associated cleaning
steps after thinning.  If there are small particles on the CCD they can
scratch the devices when we remove them.  These areas then do not oxidize
as well and the QE is lower.  We seen them equally for UV flooded
and PPtF devices.  We have never been able to see them by eye, only in flats.

-Mike