中文摘要：

HIRFL-CSR调试过程中，利用频谱分析仪实时监测束流，根据其上测的数据进行相关参数调整，改善束流的品质。本文对分析仪上观测到的现象一束流的中心频率发生突变进行了研究，主要就电子束的高压不稳定性和中性化因子的突变做了理论分析，并进行了相关的模拟计算，根据模拟结果初步断定该现象的出现由电子束的中性化因子导致。

英文摘要：

In commissioning the HIRFL-CSR （Cooler Storage Ring of Heavy Ion Research Facility in Lanzhou）, with the spectrum analyzer monitoring the beams on-line, we measured many parameters of the beam status for improving quality of the heavy ion beams. In this paper, the sudden change of the beam center frequency is analyzed. A theoretical analysis is done mainly on instabilities of the electron voltage and the neutralization factor. Simulations were made for the problem. According to the simulation result, we can conclude that it is the instability of neutralization factor that caused the problem.