A novel digital XRF based on FPGA is presented.Semiconductor detector,precision amplification and high-speed data acquisition modular circuit are described.The technical points of the digital processing are introduced in details,such as digital pulse shaping,peak discrimination and multi-channel range analysis in the internal FPGA etc.The analysis software is based on Visual C++6.0 development environment,using C++ programming language.From an actual test,the system obtains satisfied results relating energy resolution and pulse count rate etc.

A simulation method of nuclear pulse signal based on Monte Carlo method was presented in this paper.And the important technical points of direct sampling and replacement sampling in Monte Carlo were introduced.Software simulation of the negative exponential signal,the sinusoidal signal and nuclear pulse signal containing noise was achieved in VC++ integrated development environment.Simulation results show that the nuclear pulse signal simulated with Monte Carlo method can describe a real situation of radiation-site and will meet the requirements of the simulation of random nuclear pulse signal.

FPGA逻辑设计中常见的复位方式即异步复位和同步复位。大多数情况下简单的通过同步复位或异步复位虽然能够正常的完成复位功能,但并没有得到精确合理的设计,可靠性较差。本文通过对同步复位与异步复位深入的分析,并且比较了各自的优缺点。重点针对异步复位过程中的亚稳态问题采取了一种有效的可靠复位解决方式。