| 摘要 |
An improved circuit for quantifying the energy incident to a detection device in a radiography application is achieved by the present invention. The output of a penetrating radiation detection device is connected to an integrating electrometer amplifier which in turn may be connected to a variable gain amplifier which is connected to a current integrator. The summing node of the current integrator receives current related to the current output from the detection device and receives current of an opposite polarity from a charge dump circuit. An integrating capacitor is also connected to the summing node. A comparator is connected to the output of the integrator and when the output signal of the integrator reaches the comparator's reference level, the comparator triggers the charge dump circuit which places a predetermined charge on the integrating capacitor at the summing node. Because the charge dump supplies a predetermined charge level, the current related to a penetrating radiation incident occurring during the reset period is summed to the charge dump current and no latent period occurs during the reset. A resettable counter counts the number of times the charge dump circuit is triggered and this count per unit of time represents the quantity of energy incident to the detection device. |
