A NEW CONCEPT OF A HIGH-SENSITIVITY TISSUE-EQUIVALENT PROPORTIONAL COUNTER FOR INDIVIDUAL NEUTRON DOSIMETRY

This paper deals with a new concept of tissue-equivalent proportional counter for personal radiation protection monitoring. A high sensitivi ty to neutron and gamma radiation is obtained by the use of a multicha nnel cathode. Electrons and ions drift in an electric field created in each channel by a bias current inside the cathode material. Three sta ges are described, a single-channel counter with a needle anode, a one and five channel counter with a wire anode and a multicellular counte r with nine wire anodes and more than 250 channels. The first results on the electric field distribution and electron behaviour are presente d. A quasi Dirac chord length distribution is determined. An example o f the microdosimetric spectrum obtained with a monoenergetic neutron i rradiation is shown.