Study of 222Rn permeation through polymer membranes II: calibration curves of a new device equipped with a polyethylene membrane, for continuous measurement of 222Rn in water-saturated soils.

The permeation of 222Rn through plastic membranes has been studied in order to improve a solid-state measuring device BARASOL and to use it in water-saturated soils. Preliminary results show that polyethylene is the most efficient membrane (sufficiently permeable to radon and impermeable to water). In the present study, we have adapted polyethylene membranes to the BARASOL probe and tested them, in this configuration, with a special experimental set-up. We have shown that it is possible to measure radon concentrations in water of about 1 Bq L(-1) with this probe.