| Design and construct the Thorium Molten Salt Reactor-TMSR-SF1is one of the task of theproject named Advanced Fission Nuclear Energy, the strategic priority research programslunched by the Chinese Academy of Science (CAS) in2011. As a nuclear facilities, it is requiredto set a Online and Real-time Radioactive Gas and Aerosol Monitoring System in the workplaceof the TMSR-SF1for effectively control the radioactive contamination in the workplace and forprotecting workers. To this purpose, the TMSR project initialized development of the prototypeof the Online and Real-time Radioactive Gas and Aerosol Monitoring System (Pre-RGAMS).With the development of online radiation monitoring system, it is required a higherperformace on its system control, acquisition speed and accuracy, storage capacity, transfer rates.As an important partof the Pre-RGAMS，in this paper, we designed a high-precision, high speed,real-time data acquisition system and its control software according to the requiremnets for thePre-RGAMS.In this paper, firstly, several technologies have been chosen for the hardware control of thedata acquisition system for the Pre-RGAMS:1) an FPGA logic-based control technology withfully flexible control features to overcome the shortcomings of the traditional data acquisitionsystem based on system-on-chips, on low Low Digital Signal Processing (DSP) and withinflexible pin configuration.2) a high-speed ADC–based technology to achieve multi-channelsynchronous acquisition, precision amplitude conversion and high rate conversion for theaerosol signal.3) SDRAM memory-based technology to realize high-speed large-capacity dataacquisition storage. to overcome the shortcomings of the traditional FIFO memory (FIFO), smalldual-port RAM and static RAM capacity characteristics.The hardware design of the data acquisition system included the design of ADC conversioncircuit, FPGA configuration circuits, and the data storage SDRAM circuit. Altera’s Cyclonellseries EP2C8Q208C8FPGA was adopted as the main control chip. ADC AD678chip was usedfor high-speed signal conversion processing. Memory chip, modern HY57V series was chosenfor large-capacity storage signal acquisition. The system hardware circuit adopts Cyclone llseries of Altera company EP2C8Q208C8FPGA as main control chip, the ADC chip selectionAD678to high-speed switching signal processing, memory chips use modern HY57V series ofacquisition signal for the large capacity storage, using Serial port and USB data interface wereselected to collect the data for transmission. Secondly, the paper describes the software design of the data acquisition system, includingthe control software design for FPGA and PC application. Modular design was adopted for thecontrol software design for FPGA internal logics. These modules include the PLL clock module,FIFO buffer module, SDRAM controller module, PCI interface module. the module function isrealized by using hardware description language Verilog HDL. For PC applications, display andcontrol interface was developed by using a PC based on VC++6.0for making the system moreflexible control. PC application using modular programming ideas realized the parametersettings, real-time display information of the Pre-EASMS, acquisition data, and spectrum dataprocessing.Multi-threading technology on structure, including data reading and data processing twothreads improved the efficiency of the software. Algorithms for α spectrum analysis wasembedded in the PC application, and the accuracy and stability of the algorithm is also analyzed.Finally, software and hardware debugging was arried out for the whole data acquisitionsystem. In the system debugging, background in laboratory environments and measurement withstandard source were performed using the Pre-RGAMS. The measurement results show that thedesign of the data acquisition system with high-speed, high-accuracy, high-capacitycharacteristics, compared to traditional data acquisition system, and meet the designrequirements of the data acquisition system for the Pre-RGAMS. |
PDF Full Text Request