从理论和模拟两方面研究了西安质子应用装置二极铁、四极铁电源电流纹波对引出束流的影响，并根据模拟结果确定出以下单种磁铁电源电流纹波标准：对于聚焦四极铁电源，电流纹波/设定值应小于1.2×10-4；对于散焦四极铁电源，电流纹波/设定值应小于2×10-3；对于二极铁电源，电流纹波/设定值应小于4×10-4。因西安质子应用装置同步环上所有磁铁电源采用同一纹波标准，综合考虑所有磁铁电源电流纹波后，最终确定电源电流纹波/设定值应小于1×10-4。

The third resonant slow extraction and RF-knockout technology was adopted for Xi’an Proton Application Facility(XIPAF), which was designed for proton single event effects research. The influence of dipole and quadrupole power ripple on extracted spill was explored theoretically and simulated via TrackAll. According to a series of simulation results, ΔI/Iset≤1.2×10-4 for the quadrupole-focusing power converter , ΔI/Iset≤2×10-3 for the quadrupole defocusing converter and ΔI/Iset≤4×10-4 for the dipole converter are acceptable, where ΔI represents the variance of the ouput current caused by power ripple and Iset represents the standard value of the output current without ripple. Since the synchrotron’s power converters in XIPAF satisfy the same standard in terms of power ripple, it is confirmed that ΔI/Iset should be limited to 1×10-4 for all power converters.