Abstract: Background: In the workplace of the nuclear facilities, radioactive α aerosols monitoring in a fast, continuous way is required for protecting workers against radiation exposure. Purpose: Based on concentrations level of α aerosols in the workplace, α aerosol monitor was designed. The overall design scheme of the data acquisition system of the radioactive α aerosol monitor was introduced. Methods: A Cyclonell series FPGA (Field Programmable Gate Array) chip EP2C8Q208C8 from Altera corporation was applied as the control core to complete the A/D converter of AD678, data storage, and data communication with remote computer via RS485 interface. The sample data was stored in the data memory of 64 Mbit SDRAM (Synchronous Dynamic Random Access Memory) for continuous and fast sampling. Both the numerical simulation and experimental measurements were carried out to verify the reliability of the data acquisition system. Results and Conclusion: Results show that the data acquisition system can acquire and control the detector signal for the radioactive α aerosols monitor in real-time, high-precision and fast-speed.

Key words: α aerosols, FPGA, Data acquisition, A/D conversion, High precision