Abstract:
Natural radionuclides including 222Rn, 220Rn, 210Pb, 7Be have been used to examine a large variety of relevant atmospheric processes. Routine measurements of these naturally occurring radionuclides in Antarctica. Zucchelli Station and at Campo Icaro, help to understand the atmospheric composition and its variations. 222Rn, 220Rn are measured in situ with a dedicated low level alpha spectrometer working in continuous mode, with a time resolution of two hours. 210Pb and 7Be are measured on aerosol filters sampled with a high volume device every three days. Measurements are carried out in Bologna using HPGe spectrometers.
Quality
The radon monitor has been designed and built at the Brazilian Institute of Space Research for active measurement of radon isotopes. The system includes a pumping station by means of which radon present in the atmosphere is drawn, following suitable filtration and dehydration steps, through an electrostatic precipitation chamber in which the anode (or cathode) where ... decay-produced radon progeny is precipitated, is a surface barrier silicon detector allowing for their immediate alpha spectrometry. Time resolution of radon measurement is 1 hour, though in some cases integration time of signals has been extended to two hours, in order to reach an acceptable data precision and accuracy, owing to the low radon concentration at BTN. All the data were collected during the austral summer, in coincidence with the station opening. Aerosol sampling activity is carried out with a time resolution of about 3 days PM-10 High Volume Sampler (flow rate: 1.13 m3 min-1). 7Be and 210Pb specific activities are determined on the sampled quartz fiber filters by non-destructive high resolution g-spectroscopy at 478 keV and 46.5 keV respectively with HPGe detectors at the Laboratory of Environmental Radiochemistry of the Bologna University.
