The LE is the low energy telescope that is carried on Insight-HXMT. It uses swept charge devices (SCDs) to detect soft X-ray photons. LE’s time response is caused by the structure of the SCDs. With theoretical analysis and Monte Carlo simulations we discuss the influence of LE time response (LTR) on the timing analysis from three aspects: the power spectral density, the pulse profile and the time lag. After the LTR, the value of power spectral density monotonously decreases with the increasing frequency. The power spectral density of a sinusoidal signal reduces by a half at frequency 536 Hz. The corresponding frequency for quasi-periodic oscillation (QPO) signals is 458 Hz. The root mean square (RMS) of QPOs holds a similar behaviour. After the LTR, the centroid frequency and full width at half maxima (FWHM) of QPOs signals do not change. The LTR reduces the RMS of pulse profiles and shifts the pulse phase. In the time domain, the LTR only reduces the peak value of the cross-correlation function while it does not change the peak position; thus it will not affect the result of the time lag. When considering the time lag obtained from two instruments and one among them is LE, a 1.18 ms lag is expected caused by the LTR. The time lag calculated in the frequency domain is the same as that in the time domain.

LE是Insight携带的低能望远镜-HXMT。它使用扫掠电荷装置 (SCD) 来检测软 X 射线光子。LE 的时间响应是由 SCD 的结构引起的。通过理论分析和蒙特卡罗模拟，我们从功率谱密度、脉冲轮廓和时滞三个方面讨论了LE时间响应（LTR）对时序分析的影响。在 LTR 之后，功率谱密度值随着频率的增加而单调减小。正弦信号的功率谱密度在频率为 536 Hz 时减少一半。准周期振荡 (QPO) 信号的相应频率为 458 Hz。QPO 的均方根 (RMS) 具有类似的行为。在 LTR 之后，QPO 信号的质心频率和半峰全宽 (FWHM) 没有变化。LTR 降低了脉冲轮廓的 RMS 并改变了脉冲相位。在时域上，LTR只降低互相关函数的峰值，不改变峰值位置；因此它不会影响时间延迟的结果。考虑从两台仪器获得的时间延迟，其中一台是 LE，预计 LTR 会导致 1.18 毫秒的延迟。频域中计算的时间滞后与时域中的相同。