潜伏径迹是进入固体径迹探测器的重带电粒子在其中产生的辐射损伤痕迹;可蚀刻径迹是入射倾角大于临界角θ_C的那部分潜伏径迹;蚀刻后径迹是经过蚀刻剂蚀刻一定时间后在固体经迹探测器中形成的蚀刻坑;可观测径迹是蚀刻后径迹中水平投影大于某最小可观测长度l_(min)的部分。我们用计算模型——分层径迹球法计算外探测器中裂变径迹的各种分布,结果 The latent track is the trace of the radiation damage in which the heavy charged particles entering the solid track detector are generated; the erodable track is the part of the latent track whose incidence angle is greater than the critical angle θ_C; the track after etching is etched by the etchant The etching pit formed in the solid track detector after the time; the observable track is the part of the horizontal projection of the etched track larger than a certain minimum observable length l_ (min). We calculate the various distributions of the fission tracks in the outer detector by using the computational model-stratified trackball method. The results