A detector for track-nanodosimetry

In this paper, we describe a gas counter able to measure electron cluster distributions in nanometric sized sites. We designed a system of electrodes that is able to collect electrons from a nanometric wall-less sensitive volume and to transfer them to a counter that detects single electrons. Measurements of electron collection efficiency in propane gas confirm that we successfully collected electrons from a wall-less sensitive volume, of about 20 mm width, with an average efficiency of more than 20%.