| 摘要 |
PURPOSE: To measure radon daughter nuclide and thoron daughter nuclide by separately measuring radon and thoron when measuring them. CONSTITUTION: A gas to be measured is introduced into a first detection unit 30 andαrays from radon and its daughter nuclide and thoron and its daughter nuclide are detected by an ionization box 36 while capturing the radon daughter nuclide and thoron daughter nuclide at one-side electrode 46 and improving detection sensitivity. The radon daughter nuclide, thoron, and thoron daughter nuclide in the gas to be measured are eliminated by a radon extraction means 54. In a second detection unit 32, while radon daughter nuclide which is generated due to the decay at or after a radon extraction means 54 is captured by an one-side electrode 146 and detection sensitivity is improved,αrays from the radon and its daughter nuclide are detected by an ionization box 136. Radon count value and thoron count value are obtained simply and economically from the output signals in real time.
|
