Electron multiplication CCDs for astronomical applications

Electron multiplication CCDs have been commercially available for a few years but have yet to make a wider impact in the astronomical community. They have specifically been designed to use an avalanche gain process during the serial charge transfer process to give large signal gain. In all other respects they are identical to the very latest generation of low-noise CCDs. They have been used with great success in "lucky" imaging, for adaptive optics systems and also in high-speed faint object spectroscopy science programs. Their sub-electron read noise makes them an obvious choice for any observation, which is normally detector read noise limited. I present a detailed summary of the typical performance and characteristics of these devices and compare and contrast them against standard low-noise astronomical CCDs. I also present modeled and real data for these detectors with particular regard to some of their lesser known issues such as clock-induced charge. Finally, I present results from real-world astronomical testing, which shows the superior performance of these devices. (C) 2009 Elsevier B.V. All rights reserved.