热控涂层质子辐照的地面模拟研究中采用单一能量质子替代空间能量连续分布的质子，连续能量质子谱是其等效性研究的关键。提出了采用阶梯型脉冲负偏压鞘层加速技术在一个脉冲宽度内获得连续能量质子谱的方法，并利用质点网格法对所获得质子谱的剂量-能量关系进行了数值仿真研究，分析了连续能量质子谱的剂量-能量分布特征及连续能量质子谱的形成过程。结果表明: 阶梯型脉冲负偏压鞘层加速能够产生连续能量的质子谱，连续谱是每微秒区间入射到样品的质子叠加而成的，且每个区间所产生质子的能量与该区间电压值相对应，连续谱中，随着质子能量的增加，其剂量总体上呈现下降的趋势。

The performance degradation of spacecraft thermal control coatings irradiated by protons is generally investigated by using protons with the same energy in ground testing while the energy of protons is in succession in space. The irradiation equivalence of the two kinds of protons is still not well understood. In this paper, a method of producing protons with continuous energy by plasma sheath acceleration using pulse voltage with discrete steps is proposed for better analysis of irradiation equivalence. The dose-energy distribution on the sample is numerically investigated by particle-in-cell(PIC) method. The characteristics of dose-energy distribution and the formation mechanism of protons with continuous energy are then discussed. The results show that protons with continuous energy can be realized utilizing pulse voltage with discrete steps, as the energy of protons irradiating the sample overlaps between two adjacent 1 μs periods, and the energy of protons produced is closely related to the voltage on the sample in every 1 μs period. Moreover, the number of protons irradiating the sample may decrease if the proton energy increases.