Digital Multi-channel Pulse Height Analyzer Based On The FPGA And USB

In the experimental of nuclear physics, one of the main ways to obtain nuclear informations is the nuclear spectrum acquisition and analysis. The multi channel pulse amplitude analyzer is a core component of energy spectrum acquisition, its performance affects the precision and accuracy of the measurements directly. With the development of high speed ADC chip, programmable gate array (CPLD, FPGA), the digital multi-channel pulse amplitude analyzer (DMCA), as a matter of fact, is becoming one of the important development direction of pulse spectrum techniques, because of its flexible design, filter forming ability, fast processing speed, strong anti-interference ability,etc.In this paper, we use an ADC+FPGA+USB and PC software collaborative work plan to design a DMCA base on the Altera’s Stratix III EP3SL150N development board. The ADC chip, we use the AD9254. In FPGA chip design, we combine the software and hardware, to design a SOC based on the FPGA chip, mainly to complete the threshold discrimination, filtering, amplitude extraction, data storage and transmission. The USB chip, the EZ_USB_CY7C68013A, transfers the data to PC. The PC software, we use the NI VISA to driver USB chip, and the Labview software to receive the data from the USB chip and then store them. The Matlab software is to complete the statistics and calculation and finally display the energy spectrum. This whole system adopts a pipeline architecture, and it can filter the input signals real-timely, process data and display the spectrum online.Through the experiments, the performance indexes of the DMCA are match the requirements of the MCA. We use the DMCA to measure the137Cs and60Co’s energy spectrums, and the energy spectrums have good energy resolution and linearity.