The effective point of measurement for depth‐dose measurements in small MV photon beams with different detectors

Purpose The effective point of measurement (EPOM) of cylindrical ionization chambers differs from their geometric center. The exact shift depends on chamber construction details, above all the chamber size, and to some degree on the field‐size and beam quality. It generally decreases as the chamber dimensions get smaller. In this work, effective points of measurement in small photon fields of a range of cylindrical chambers of different sizes...