| 摘要 |
PURPOSE:To cover the detection of leakage radiation over a wide area by making light having specified intensity incident on one end of a quartz optical fiber coil, detecting the intensity of the light emitted from the other end and displaying the output thereof or the amplified output. CONSTITUTION:When the radiation leaked from a nuclear reactor vessel 1, the radiation pass through the inside of an optical fiber coil 2 and therefore the transmission loss of the core of the optical fiber is increased by the gamma rays among the radiation. The quantity of the light passing through the coil 2 decreases consequently and the photocurrent of a photodetector 6 decreases. The value of an output level meter 8 decreases as well and an alarm is sounded when the value decreases down to the critical value or below. |
