Camera for ground-based astronomy: J-PAS CryoCam
For the Javalambre Physics of the Accelerating Universe Astrophysical Survey, J-PAS, a 2.5m ground telescope in Spain funded by a consortium of Spanish and Brazilian astronomy institutes, Teledyne e2v is ready to deliver a 1.2 Gigapixel camera. The Teledyne e2v camera subsystem has an extremely large field of view and sensitivity, which will enable it to perform an unprecedented photometric survey of 8,500 square degrees of the sky. This will help to build a 3D map of the Universe, while obtaining precise redshifts (better than 0.3 % accuracy) for more than half a billion galaxies. The combination of redshifts precision and sheer numbers, unmatched by any other existing survey, will provide astrophysics with unprecedented knowledge about dark energy and the evolution of galaxies.
- Exceptional flatness and thermal and mechanical stability of the focal plane – 27μm peak to valley measured at -110oC and room temperature, surpassing the customer’s requirement
- Fast read-out time – under 20 seconds
- Extremely low noise – less than 5 e- at 400KHz, surpassing the customer’s requirement
- Excellent cooling stability over long durations – better than +/- 1oC
Teledyne e2v’s Camera Architecture
- At its core the Teledyne e2v camera has a 450 mm focal plane made up of 14 e2v’s 9k x 9k pixel CCD290-99 scientific image sensors. These are backthinned, with anti-reflection coating for maximum sensitivity. The array also features 12 auxiliary image sensors for guiding and focusing (comprising 4 CCD47-20 Autoguider sensors, 8 CCD44-82 Wavefront sensors).
- 22 CCD Drive Modules control the CCDs and process their output though Digital CDS (Correlated Double Sampling) readout electronics. These optimise the CCDs’ performance from multiple outputs and devices simultaneously. Each science and guide sensor is controlled by one drive module whilst two wavefront sensors share a drive module.
- The 22 CCD drive modules contain 70 field programmable gate arrays (FPGAs) and 24 Complex Programmable Logic Devices (CPLDs) in 13 different designs to enable to read 2.4 GBytes of data/frame.
- Power and data handling electronics.
- The focal plane is contained in a custom cryogenic cooler with integrated electronic control (PLC) for cooling and vacuum systems control, which provides low noise and maximum sensitivity.