Comparison of Point Spread Function in p- and n-Channel CCDs

This paper presents a brief review of charge-redistrbution effects in charge-couple devices observed in both flat-field and spot data. Experiments are described that allow such phenomenon to be measured simply in the parallel transfer direction using only equipment capable of providing flat-field illuminations. A more detailed investigation into signal-dependant PSF shape distortions are descibed for both p- and n-channel CCDs of identical design. A number of methods to minimise the effect are presented that include different image electrode configurations and bias levels during integration and novel pixel architectures