μDose: A compact system for environmental radioactivity and dose rate measurement

mu Dose is a novel compact analytical instrument for assessing low level U-238, U-235, Th-232 decay chains and K-40 radioactivity. The system is equipped with a dual alpha/beta scintillator allowing discrimination between alpha and beta particles. The unique built-in pulse analyzer measures the amplitude of each individual pulse, its shape and the time interval between subsequent pulses. This allows the detection of pulse pairs arising from subsequent decays of Bi-214/(214)po, Rn-220/(216)po, Bi-212/(212)po and Rn-219/Po-215. The obtained alpha and beta counts and four separate decay pair counts are used to calculate U-238, U-235, Th-232 and K-40 specific activities in measured samples through the use of radioactivity standards. The mu Dose system may be equipped with various photomultipliers and counting containers to assess radionuclide concentrations of samples of masses ranging between 0.4 g and 4 g. As a result, the user can customize the system to their needs and maximize the instrument's performance. The system is controlled by dedicated software with a graphical user interface and modules for system calibration, data visualization, specific radioactivity calculations and dose rate determination using the infinite matrix assumption.