A simple and versatile 222Rn/220Rn exposure chamber

A simple 222Rn/220Rn exposure chamber is described. The chamber is made of acrylic and has a volume of 0.41 m3. The 222Rn and 220Rn sources can be operated independently or simultaneously. The concentrations of 222Rn and 220Rn were monitored by a continuous alpha spectrometer called RAD7. The capability of alpha spectrometry has removed the mutual interference between 220Rn and 222Rn, which is a major problem in measuring 220Rn. Furthermore, the capability can also provide fast response to changes in the 222Rn level and 220Rn level in the exposure chamber, with temporal resolutions of about 20 and 2 min, respectively.