Characterisation of 3He3He proportional counters

This paper describes the characterisation of a set of 3He3He proportional counters differing in gas composition and pressure. Each step of the signal generation in the detector is analysed. Optimal working conditions are defined in order to choose the high voltage to be applied. Dead time with short shaping time is measured in such optimal conditions. In addition, the overall neutron efficiency and the gamma sensitivity are reported. Such characterisation is required for a correct choice of the associated counting electronics and the applications of the counters.A complete pulse processing modular system, consisting of a pulse height analysis system and a pulse correlation analysis system equipped with a time of arrival recorder, is used for the characterisation.