Design Of The Data Acquisition System For Time-of-flight Mass Spectrometer

Time-of-flight mass spectrometer (TOF MS) is widely used in the aspects of chemistry analysis, organic analysis and isotopes detectation cause of its large dynamic range, high scan speed and brief architecture. To achieve large dynamic range and high resolution, TOF MS's data acquisition system is required to subtly record the shape of the ion detector's output pulse.This thesis describe the design of a 2Gsps high speed data acquisition system based on PCI bus. According to the requirement of large dynamic range and high resolution and the specific demand of Nationl Institute of Measurement, a very high speed analog-to-digital conversion system is employed to record the ion peaks.In the certain design, we employ interleaved sampling ADCs to realize the sample rate of 2Gsps, adopt differential transmission to guarantee the signal integrity, use DDR SDRAM and programmable logic device to implement high speed data storage and bus interfacing. As a master device on PCI bus, our data acquisition system transmits high speed data flow to the computer in DMA mode.Some background information of TOF MS and its data acquisition is introduced in Chapter 1. The following Chapter 2 contains the knowledge of general data acquisition system and analog-to-digital conversion technology. The significant Chapter 3 and Chapter 4 demonstrate the system scheme and technic details respectively. Chapter 5 gives some test result of the system while the last chapter summarizes the design process.