Introduction

In a number of ACIS memos issued by K. Gendreau and G. Prigozhin some years ago numerous techniques were suggested for determining a depletion depth of a CCD. All of the suggested techniques were very complicated and not too accurate. Described here is the most simple, efficient and stable technique. It is not sensitive to the way the events are counted (for example, reasonably small changes in thresholds do not affect the result), does not require any assumptions about the potential profile, and, probably, the most important, depletion depth can be extracted from just one dataset of Fe⁵⁵ data (no need to step through the range of voltages, for instance).