|
内容記述 |
Ground and surface water usually contains a certain amount of radionuclides, including radon, which dissolves from rocks and soil into water. Methods such as bubbling or liquid scintillation for measuring radon in water have some disadvantages. Therefore, a passive, cheap and effective method based on CR-39 chips may be a good candidate for wide-ranging of surveys where the transportation of water samples would be troublesome. The proposed detector is based on a combination of a CR-39 chip (as a detectors) with a polycarbonate foil (as a radiator) acting as a radiator due to the fact that they have different partition coefficients. In this radon detector, alpha particles from the absorbed radon and its decay products can escape from the radiator, enter the detector, where they can be recorded and counted after appropriate chemical etching. The detectors were exposed in water wells located in Lądek-Zdrój, Poland and in water obtained from the deep well located near Kobe Pharmaceutical University, Japan. Two methods, grab sampling liquid scintillation method (LSC) used as reference and integrated measurement method (CR-39) were compared. Track density of CR-39 covered by MAKROFOL foil was compared to track density of CONTROL detectors (without MAKROFOL). It can be concluded that the MAKROFOL foil used as radiator allow to increase response sensitivity of CR-39 chips by a factor of more than 10 times. |
