| 摘要 |
A relatively small diameter, relatively deep hole is made in the ground and a sampler tube is inserted therein. An acetate sleeve is detachably inserted into a chamber on the upper end of the sampling tube and the sampler is left for at least sixteen hours and preferably longer in order to permit radon gas to migrate up the tube. Daughter products of radon deposit on the acetate film which is then placed in a scintillation cell attached to the counting chamber of a scintillation counter, which counts the alpha emissions of the daughter products thereby permitting the amount of radon gas to be calculated. This method reduces considerably any contamination of the scintillation counting chamber so that cleansing is not necessary thus permitting a much higher level of productivity. The system is also totally insensitive to thoron so that no correction for thoron signals is required. The same method can be used to collect airborne samples by hanging the acetate strip in a desired location for at least four hours and counting alpha emissions from said strip as above.
|
