The beam loss on the beam line is analyzed after the introducing of principle and structure of nbi system . the beam absorption targets are designed for measuring the lost beam power , and as an emphases , the calorimeter is designed in detail to measure the beam power and the distribution of beam power density 本文在介绍了中性束注入系统原理和结构基础上，对束线上束流损失进行了分析，设计了束流吸收靶测量损失的束功率，同时重点设计了功率测量靶以测量束功率和功率密度分布。
Secondly , the beam orbit offset effects caused by the initial beam offset and the linac components " offsets have been quantitatively studied first . as an example with the injector linac for beijing electron positron collider upgrading project ( bepcii ) , the beam orbit offset caused by the above error effects have been simulated and analyzed 其次定量研究束流的初始径向误差和加速器部件的安装误差等对束流轨道偏轴的影响，并以北京正负电子对撞机二期工程( bepc )的直线加速器为例，给出了上述各种误差导致轨道偏轴的模拟计算结果及其分析。
