Description
Abstract:
To address the beam diagnostics requirements of multiple cyclotrons at the China Institute of Atomic Energy (CIAE), a multi-channel digital beam diagnostics electronics system based on current-to-voltage (I/V) conversion was developed. The I/V conversion circuit integrates high-precision operational amplifiers featuring ultra-low bias current and low-temperature-drift resistors. The system implements a hybrid filtering architecture: combining analog and digital filters. The analog filters comprise a first-order RC filter and a second-order MFB low-pass filter, while the digital filters consist of FIR, median, and MAF filters. The Xilinx Artix-7 series FPGA(XC7A100T-2FGG484I) serves as the main controller and an 8-channel, 18-bit ADC is employed for signal digitization. The User Datagram Protocol (UDP) is adopted for communication between the electronics system and the host PC or PLCs. Test results show that a maximum relative error of 0.5% is achieved when the beam current ranges from 100 pA to 20 mA, with a linearity coefficient (R²) greater than 0.999999 for all channels. The system has been validated through long-term operation on CIAE’s high-current accelerators (e.g., BNCT and neutron-imaging accelerators equipped with the 16-channel electronics) and low-current accelerators (e.g., 16 MeV and 9.5 MeV cyclotrons equipped with the 8-channel electronics).
