Abstract: Improving measure accuracy and system security of nuclear instruments is of great importance. In general, improving accuracy will cause a decrease in system security and response speed. So a new sliding-window accumulation algorithm was given, which could improve measurement accuracy in radiant intensity detection, and the system security and response speed remain largely unchanged at the same time. A detailed algorithm analysis based on Monte Carlo method was presented, which indicated the scope of application of the algorithm.

Key words: data accumulation algorithm, relative error, response speed, system security, Monte Carlo method