We studied the locklock loss happend at 01:44:32, Nov 11, 2024 (JST). We found that K1:LSC-TR_IRY_NORM_OUT_DQ starts to decrease from 8 sec before the lockloss (see Fig1). Starting from counts~140, it becomes almost constant (~100) from 5 sec before lockloss, but it goes to 0 at lockloss. We checked other channels by ndscope, PEM channels (ACC, MAG, MIC) and VIS by Pastavi.
- This lockloss had continued until Yokozawa-san recovered IMC lock (https://klog.icrr.u-tokyo.ac.jp/osl/?r=31559). It is found that the earthquake happens at 3:01JST, but this earthquake would not be the reason of this lockloss.
- We found a strong peak at 8 sec before the lockloss in whitened spectrogram of K1:VIS-PRM_TM_WIT_[P,Y]_DQ (Fig 2, 3).
