Persistence and charge diffusion in an E2V CCD42-90 deep-depletion CCD

The ESPaDOnS spectrograph at the Canada-France-Hawaii Telescope was recently upgraded to use an E2V CCD42-90 deep-depletion CCD. While changing to this device from a standard silicon CCD42-90 had many benefits such as much higher red QE and much lower fringing, it was also found that the new device exhibited persistence. After talking with E2V, a solution to the persistence was found, but this resulted in reduced resolution on the spectrograph from charge diffusion. This paper will describe the solution found to allow the detector to run with no persistence and with limited charge diffusion.