| 摘要 |
A method and apparatus are described for reducing or removing the background noise caused by thoron gas (220Rn) in uranium exploration conducted by the detection of radon gas (222Rn) emanating from the ground. This is accomplished by the use of a number of alpha particle detectors, each of which is disposed in a protective enclosure. A barrier which permits, but deliberately retards, the passage therethrough of gases is disposed in the path to be traversed before such gases can reach the alpha particle detector. The increase in the transit time made necessary by requiring soil gases to move through the barrier should be sufficiently long to allow the decay of most of the thoron, thereby eliminating its contribution to the total signal reflected at the detector. |
