  The background caused by radon and its daughters is an important background
in the low background liquid scintillator (LS) detectors. The study of the
diffusion behaviour of radon in the LS contributes to the analysis of the
related background caused by radon. Methodologies and devices for measuring the
diffusion coefficient and solubility of radon in materials are developed and
described. The radon diffusion coefficient of the LS was measured for the first
time and in addition the solubility coefficient was also obtained. In addition,
the radon diffusion coefficient of the polyolefine film which is consistent
with data in the literature was measured to verify the reliability of the
diffusion device.
