| 摘要 |
<p>PURPOSE:To improve the measurement accuracy of mean density and increase a measurable distance by moving a gamma-ray source and a transmission type gamma-ray detector, which are inserted into investigation holes digged in the ground almost in parallel, along the investigation holes. CONSTITUTION:The nearly parallel investigation holes 1 and 4 where the gamma-ray source and gamma-ray detector are inserted respectively are digged in the ground A at a specific distance. Further, an insert tube 3 where the gamma-ray source 2 is put atop is inserted into the investigation hole 1 and the probe 5 equipped with the transmission type gamma-ray detector 6 is inserted into the investigation hole 4. The gamma-ray source 2 in the investigation hole 1 and the gamma-ray detector 6 in the investigation hole 4 are moved up along the investigation holes 1 and 4 respectively and the gamma rays from the gamma-ray source 2 are detected by the gamma-ray detector 6 to measure the density of the ground, thereby investigating the ground state between the investigation holes 1 and 4.</p> |
