The Miniature Data Acquisition System On Gamma Camera

As nuclide is used more and more into people’s lives, more species produced inthe surrounding environment of radiation will be invisible. Now, It is becoming a hotspot of radiation testing about how to quickly detect the nuclide in the radiationintensity and the location of the environment. Gamma camera is a nuclide detectioninstrument, Its sort is various, mainly contain medical gamma camera andenvironment detecting gamma camera. This paper mainly discusses the small gammacamera about the environment detecting of the data acquisition system.FPGA technology has been widely used in the high-speed signal acquisitionsystem.In this paper, The high-speed signal acquisition is based on the FPGA technology.Because the detection requirement is256channels and compared with theconventional A/D conversion module, we make a reference voltage which not onlysimplified the circuit but also reduces the production cost, The detection device isadopted Japan marina pine company of256anode H9500photomultiplier tubes, andadopt the Altera corporation of CycloneIII series FPGA as the core of the informationacquisition module. Data acquisition module uses the CAN bus to communicate withthe upper software, In this time, we chose the Silicon Labs company C8051F500single-chip microcomputer as the CAN bus communication control chip, which canbe effective to ensure that the position of the upper and lower signal acquisitionmodule of communication rate, facilitate the programming, reduce the developmentcycle.In the hardware, This paper mainly introduces the design of hardware circuitbased on FPGA, And introduces the amplification circuit, comparison circuit, FPGAcircuit and system design of CAN bus circuit. In the software, This paper mainly introduces the FPGA design and FPGA,between C8051MCU and host computer communication. The development tool ismainly used in computer programming by Microsoft Visual Studio2005.When the data system is completed, we make a practical testing. As the result ofthe test, the system works stability and can achieve the desired results. and the systemhas the advantages of small volume, fasting response speed, being easy to transplant,It has the value to the research of the environment detection.