Improvement of the detection limit by radon background reduction method

Abstract

This paper describes a simple method to reduce the radon background component applied in environmental studies using gamma spectrometry. The radon component can be reduced by introducing either nitrogen gas or clean air into the detector chamber in order to create a positive pressure and further minimize radon intrusion from outside. This method shows that we can minimize the influence of radon daughter background such as ²¹⁴Pb, ²¹⁴Bi and ²¹⁰Pb (from ²³⁸U), ²¹²Pb, ²¹²Bi and ²⁰⁸Tl (from ²³²Th). By the way, the detection limit of the gamma spectrometry is discussed.