【摘要】 脉冲发生器可为飞行时间二次离子质谱仪(TOF-SIMS)各部件提供精确的工作时序,确保整机正常工作。基于FPGA/NIOS II技术,整个装置具有集成度高、设计灵活的优点。针对TOF-SIMS对延时精度的要求,该装置采用FPGA内部计数器实现10 ns以上的粗延时,用简化后的斜坡电路实现10 ns以下的细延时,并对斜坡电路进行误差分析。实测本脉冲发生器延时分辨率达100 ps,输出信号峰峰值抖动小于200 ps。TOF-SIMS仪器锆石谱图测试结果表明,脉冲发生器的指标满足整机仪器的要求。更多还原

【Abstract】 The pulse generator provides precise working sequence for time of flight secondary ion mass spectrometer(TOF-SIMS),and ensures the instrument normal running. The pulse generator is based on FPGA/NIOS II,and has advantages of high integration and flexible design. According to the requirements of delay precision made by TOF-SIMS,the unit adopts counter in FPGA to achieve coarse delay that exceeds 10 ns,and adopts slope circuit which is simplified to achieve fine delay that below 10 ns. There is an error analysis for slope circuit. Its delay resolution is measured as100 ps and output peak-to-peak jitter is less than 200 ps. The result of the zircon spectrum of TOF-SIMS instrument demonstrates that the pulse generator parameters meet the requirements of the instrument.更多还原