The Direct Ion Storage dosemeter for the measurement of photon, beta and neutron dose equivalents

The physical basis for the DIS (Direct Ion Storage) dosemeter is reviewed along with some of the issues associated with the expected long-term stability and reliability of the MOSFET structure under various operating conditions. Recent data from tests performed to assess the dosimetric accuracy, stability and reliability of the first commercially produced units for photon and beta radiation is presented. Special detectors have been developed for neutron dosimetry. Their design may be optimised either for a flat energy response or for a very high sensitivity at thermal neutron energy. Results of test irradiations in neutron fields from thermal up to 45 MeV neutron energy are presented with indication of dependence of the detection limit for neutrons on the photon dose for various dosemeter designs.