An electron bombardment CCD-camera as detection system for an echelle spectrometer

The electron bombardment CCD (EB-CCD)-camera system is a very sensitive detector designed mainly for low-light imaging applications. The major advantage compared to a microchannel plate intensified CCD system is the superior spatial resolution due to the special amplification system. This property would make it an ideal detection system for a high-resolution echelle spectrometer, where high sensitivity in combination with high spatial resolution is required. However, we found that part of the light focused on the photocathode of the EB-CCD is transmitted through it and detected on the CCD chip as a diffuse spot. Thus, it lowers the signal to background ratio and can lead to ghost peaks. The problem becomes particularly serious when detecting emission lines of very different intensities.