Preliminary results of CCD characterisation at ESA in support of the Euclid visible channel

摘要

Euclid is the ESA mission to map the geometry of the dark Universe using two cosmological probes, namely WeakLensing and Baryonic Acoustic oscillations. The visual imager, a CCD based optical imaging channel will be used tomeasure the shapes of galaxies in one single wide visual band spanning the wavelength range of 550-920 nm. The focalplane array supports 36 CCDs (4k×4k pixels each) with 0.101 arcsec pixel platescale, giving a geometric field of 0.55degsup2/sup. With the weak lensing technique, the mass distribution of the lensing structures can be traced back.The originally baselined CCDs were e2v CCD203-82. Following the results from a dedicated radiation damage testactivity on their CCD204 variant, a new version, called 273 has been designed and made available in a front-illuminatedversion in April 2012.For Euclid, the accuracy with which the shape of the galaxies has to be measured is considerable: 1% and has never beendemonstrated. The radiation damage effects will adversely affect this measurement and thus need to be characterized.Therefore, several test campaigns on the characterization of the CCD radiation damages for Euclid are carried out byESA and by the Euclid Imaging Consortium.For this purpose, a test bench has been implemented at ESTEC to characterize CCD devices, with radiometricmeasurements, point source illumination and lab simulation of typical Euclid sky images. The preliminary resultsobtained at ESA on a non-irradiated front-illuminated Euclid prototype CCD 273-84-2-F16 will be shown in this article.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.