| 摘要 |
PURPOSE:To simplify the constitution of a preamplifier and to use only one signal transmission cable between the preamplifier and a monitor, by using a wide band pass preamplifier of which the input impedance and gain are freely changed corresponding to the frequency band of neutron detection output. CONSTITUTION:When the detection output of a neutron detector 17 is applied to a preamplifier 19, the input impedance of the preamplifier 19 continuously and automatically changes in a high frequency band by a resistor R1, a bypassing parallel condenser C1 and a resistor R2 in series to the resistor R1 so that the detection output becomes smaller toward a high frequency band. With this change, the gain of a wide band pass amplifier circuit 19b also automatically changes so as to become higher toward the high frequency band. Therefore, the change-over or gain adjustment of amplified output becomes unnecessary and the constitution of the preamplifier of a wide range neutron flux monitor apparatus becomes simple while only one signal transmission cable is used between the preamplifier and a monitor. |
