In Situ field determination of radioactive contamination in soil using a wall-less gas flow proportional counter

A current method of site characterization involves techniques to gather field samples, package and transport them to laboratories to be analyzed. A detector is proposed to quantify contamination in the field to eliminate some problems associated with laboratory analysis. The detector is a wall-less gas flow proportional counter that uses 10P as its fill gas. Proportional counters rely on gas multiplication, which requires large values of the electrical field. The gas multiplication factor for cylindrical geometry was applied to find the optimal voltage, anode wire radius, and cathode inner radius. Energy resolution and detection efficiency calibrations were characterized. Field investigation results will verify usability and accuracy in quantifying radioactivity in soil. This detector is intended to eliminate some sample preparation and analysis. It will provide real time results of concentrations of radioactive contaminants in soil, thus speeding up site characterization and reducing cost. It also allows in-field determination of whether clean-up goals have been achieved and can be used to monitor clean areas for unintentional radioactive spills