Takuya M, Kiwamu I,

It is our pleasure to announce that the PR3 mirror still slips. The size of the slippage is larger than 300 urad, meaning the size was so big it went out of the optical lever's linear range. It went to the negative direction in pitch as seen by the optical lever.

This time, it slipped when we were trying to engage the optical lever loop feeding back to the mirror. See the  attached time series for more detail.

Also, later on, we fixed the alignment by moveing the IM picomotors with success.

[EDIT]

We then again tried to close the yaw loop and it slipped again (the second time today). This time, the mirror slipped toward the positive side in pitch as seen by the optical lever. However, the size was not as big -- it was +140 urad.