Intercomparison of thoron measuring devices in the RRI thoron calibration chamber

Recently, a thoron chamber was developed at the Institute of Radiochemistry and Radioecology, but the examinations performed up to now have shoed that development of the chamber is necessary for its more precise operation. In this work, as a first step of this development procedure, an intercomparison measurement of several active devices (SARAD EQF 3120, SARAD RTM 2100, RAD7) and scintillation systems (PYLON AB-5, NDI) have been carried out in the thoron chamber. Based on the results, the PYLON AB-5 system has been chosen as reference instrument. Correction factors for the other instruments have been given in this work. Calibration factors have been calculated for each device through the calibration of several CR-39 chips. Some of the parameters of the chamber have been determined, like thoron and progeny concentration, in a function of time and the ratio of attached and unattached EEC fraction