CCD Characterization

Characterization of CCDs is of fundamental importance when devoloping scientific instrumentation for optical and ultraviolet astronomy.

If the detector has to be mounted on a instrument the characterization is used to optimize the performances of the CCD. That means, for example, choosing the best set of working voltages, setting the gain of the amplifier in such a way to sample properly the read out noise, measuring the quantum efficiency for the suitable exposure time estimation.

Characterizing the detector allows also to supply the manufacturers with the feedback necessary to improve the detector's performances.

Within this framework we have developed a test capability which allows us to perform:

• optimization of the CCD working parameters (gate voltages, clock speed, waves shape, temperature),
• dark current, dark signal non-uniformity and read out noise characterization,
• gain and charge transfer efficiency (gain - CTE) measurements,
  
• quantum efficiency (QE) measurements in the 125 - 1100 nm range,
  
• uniformity measurements,
  
• intra-pixel response and charge diffusion vs wavelength.

Relevant characteristics of some CCDs are here.