DISCRIMINATION OF AIRBORNE RADIOACTIVITY FROM RADON PROGENY

Naturally occurring radon and thoron progeny are the most interfering nuclides in the aerosol monitoring system. The high background and flu ctuation of natural radioactivity on the filter can cause an error mes sage to the aerosol monitor. A theoretical model was applied in the si mulation of radon and thoron progeny behavior in the environment and o n the filter. Results show that even a small amount of airborne nuclid es on the filter could be discriminated by using the beta:alpha activi ty ratio instead of gross beta or alpha counting. This method can incr ease the sensitivity and reliability of real-time aerosol monitoring.