Dosimetric characteristics of a novel personal dosemeter based on direct ion storage (DIS)

A new dosemeter type has been developed and made commercially available by RADOS Technology Oy. This system is based on a never detector type, an ionisation chamber with so-called direct ion storage (DIS). This principle allows for the construction of a small and low cost passive device as well as for an active personnel dosemeter with alarm functions. Energy dependence is determined by the wall materials used for the construction of the small (approximately 1 cm(3)) ionisation chambers and can easily be modified. Tests on prototype dosemeters have been performed in the photon energy range from 8 keV to 1250 keV and with beta radiation from a Tl-204 source (E(beta max) = 0.8 MeV). The preliminary results obtained so far show that the system has a unique potential for a future legal electronic dosemeter.