SNDICE : a direct illumination calibration device for SNLS
E. Barrelet (IN2P3), C. Juramy (IN2P3), K. Schahmaneche (University Paris Diderot), P. Antilogus (IN2P3), Rohendra Attapatu (CFHT), Tom Benedict (CFHT), Gregory Barrick (CFHT), Jean-Charles Cuillandre (CFHT), Kevin Ho (CFHT), Sarah Rosser (CFHT), Derrick Salmon (CFHT)

Abstract: The goal of the SNDICE (SuperNova Direct Illumination Calibration Experiment) scheme is to improve photometric accuracy of Megacam to help reduce systematic errors affecting SNLS. This instrumental calibration will use a calibrated source including several LEDs covering the whole spectral range of Megacam. The source will illuminate directly the primary mirror with a conical beam covering the focal plane. Associated to this source, several calibrated cooled photodiodes located at different places at the level of the primary focus., We claim a relative precision of 0,3%25 and an absolute calibration with a 1%25 accuracy., SNDICE will be set up at autumn 2007.