| 摘要 |
PURPOSE:To realize secure radiation detection which allows a measurement to be taken many times by using an MOS transistor (Tr) as a radiation sensor and monitoring its characteristic parameter. CONSTITUTION:A processing circuit 4 is stored with irradiation characteristics of an N type MOSTr14 previously. Then a gate voltage measuring instrument 3 controls a voltage generator 2 to lower a gate voltage VS gradually from the threshold level of nonirradiation. Then, the circuit 4 detects variation in the load resistance voltage VD of the drain from a nonconductive state to a conductive state. Namely, variation in voltage VD from the 0 level to the source applied voltage VS is detected from the load resistance voltage and the current threshold voltage is inputted from the measuring instrument 3. Further, irradiation characteristic data in the processing circuit 4 is compared with the threshold voltage to calculate integral dosage D, which is outputted to a display circuit 5 to display the result. |
