Ali Ebrahimi - Alborz Electric Power Distribution Company, West area
Mohammad Afshar - Nuclear Engineering, Graduate University Advanced Technology, Kerman, Iran
Mohammadreza afshar - Electronic power & machine engineering , Imam Khomeini International University ,Qazvin,Iran

Background: In the medical imaging system, high precision detectors and low noise are used to extract the desired image quality. The amplitude of the output signal from these detectors is very low (from pico-ampere to micro ampere) and therefore directly undetectable. Therefore, to measure these signals with very low amplitude, the necessary processing should be done on it and then measured. The signal processing system of the detector is composed of different components, depending on the application and purpose of the design. To count the output signals of the detector, the signal must be sufficiently amplified before being entered into the counter to be prepared for counting by the counter. The task of preparing and amplifying the signal for counting by the counter is by the pre-amplifierMethods: Preamplifiers designed in institutes and research institutes related to signal processing from high and low speed noise. The reason is that the designers use an operational amplifier in the circuit design to impedance matching and amplify the signal. Preamplifier Designed by in this paper, we used field-effect transistors to impedance matching and amplification, which has a high speed at the rise time of signal and better impedance matching.Results: Designed and built in single-channel, fast, charge-sensitive, low-noise, and for most detector type. Designed input impedance is 500 ohms and output impedance is 50 ohms. To convert the current input signal to the voltage, the input high input resistance is used. The bandwidth of this device is around 50 MHz and Gain is 100. The pulse output rise time is 10 ns and its decay time is 30 microseconds, which can be changed according to the type of detector response.Conclusion: Designed load pre-amplifier is a strategic product in the nuclear electronics industry. The pre-amplifier is the first component of the signal processing components of the X-ray Imaging System. The pre-amplifier has the task of matching the impedance between the detector and the other signal processing system. The pre-amplifier design is superbly designed and has an effective 10 nV. The pre-amplifier power consumption is 15 mW.

preamplifier, gain, noise, signal processing, imaging